Sandy substrate for aquarium

The invention relates to a technology for the production of non-metallic building materials from sand and gravel rocks containing a large amount of hard-to-erase lump clay. In the method of sampling and cleaning gravel and sand, the washing of the corresponding flow is carried out in a rotating drum, the mixture into which is fed along spiral paths in a cascade mixing mode, using pressure jets of water directed to the stream of gravel or sand to be cleaned mixed in the rotating drum, while the supply jets of water are carried out through the nozzles installed coaxially along the axis of rotation of the drum and interconnected with the possibility of relative coaxial angular displacement, the water nozzles of which are located in a row, and the washed particles and sludge, as well as crushed pieces of clay are removed through windows with calibrated sieves located along the length of the drum, the unloading of cleaned gravel or sand is carried out through an unloading device located on the upper end of the drum and made in the form of a grate lattice nozzle fixedly connected to the frame of metal rods rolled into rings and covering the upper end of the drum, and also installed with a gap along the axis of the latter, and the drum spirals are performed beyond the latter from the unloading side and rotating in the grate unloading device nozzle. EFFECT: increased efficiency of extraction of clay and cleaning of gravel and sand, obtaining high-quality gravel and sand, as well as reducing energy consumption for technological operations. 2 n.p. f-ly, 4 dwg

Drawings for RF patent 2279317

The invention relates to a technology for the production of non-metallic building materials from sand and gravel rocks containing a large amount of hard-to-erase lump clay.

There is a known method of producing clay and cleaning gravel and sand, which consists in crushing and screening the original rock to obtain a sand-gravel mixture, sampling lump clay by a dry method due to the use of different elasticity of grains of sand-gravel mixture and lump clay and differences in the trajectories of their expansion upon impact o beaters of a rotating rotor, dividing the sand-gravel mixture into two streams, characterized in that the sand-gravel mixture is directed to drums rotating at a critical speed, in which the flow of sand and gravel is provided with a "waterfall" mode of movement with vibration vibrations along a circular path and its subjected to erosion by cutting action of pressure rapidly rotating jets of water in the form of a "ruff", while the sandy-clay pulp is separated from the stream of cleaned gravel for further sand cleaning and sorting.

The disadvantage of the known method of sampling clay and cleaning gravel and sand is the significant energy consumption of the process associated with the creation of critical modes of rotation of the sorting and washing drums, providing a "waterfall" mode of movement of the sand and gravel mixture in combination with its vibrational vibrations, as well as energy consumption for creating significant pressure in the cutting water jets in combination with their rotation around the axis of the sorting and washing drums. Inertial dry removal of lump clay at the stage of obtaining a sand-gravel mixture from the initial rock is also a rather energy-intensive technological process.

Technologically closest to the proposed method is the method of sampling and purification of gravel and sand, including screening, separation of the mixture into two streams previously cleaned from clay particles, divided feed of each gravel stream and sand flow for washing, transportation of the cleaned gravel and sand to warehouses (in dump) and sludge in the sump.

The disadvantage of the known method for sampling clay and cleaning gravel and sand is the ineffectiveness of washing out lumps of clay and separating adhered particles from gravel and sand by arbitrarily oriented streams of water from the conduit, as well as the significant energy consumption of the process of cleaning the mixture from particles of adhered clay and its pieces when creating high pressures in water conduit.

The low quality of cleaning is due to the removal of water and clay sludge in a counterflow along the entire length of the drum due to the lack of additional removal of sludge along the entire length of the drum, which is why, to obtain high-quality cleaning of gravel and sand, precise adjustment of the operating mode of plants implementing the known method is required: water flow rate at the frequency of rotation of the drum, with the angle of its inclination, the diameter of the drum, step and height of the flanges of its spiral internal winding both for gravel and sand.

The technical result of the proposed method for sampling clay and cleaning gravel and sand, including screening, dividing the mixture into two streams previously cleaned from clay particles, separate feeding of each flow of gravel and a flow of sand for washing, unloading and transporting the cleaned gravel and sand to a dump and sludge to sedimentation tanks, is achieved by the fact that the washing of the corresponding flow is carried out in a rotating drum, the mixture is fed into which is carried out along spiral paths in a cascade mixing mode, with the help of pressure jets of water directed to the cleaned flow of gravel or sand mixed in a rotating drum, while the water jets are supplied carried out through nozzles installed coaxially along the axis of rotation of the drum and connected to each other with the possibility of relative coaxial angular displacement, the water nozzles of which are located in a row, and washed particles and sludge, as well as rubbed pieces of clay are removed through windows located along the length of the drum with calibrated sieves, the unloading of cleaned gravel or sand is carried out through an unloading device located at the upper end of the drum and made in the form of a grate lattice nozzle fixedly connected to the frame, rolled into rings and covering the upper end of the drum, and also installed with a gap along the axes of the latter, and the spirals of the drum are designed to extend beyond the latter from the unloading side and rotate in the grating nozzle of the unloading device.

The technical result in obtaining high-quality gravel and sand used as a building material is achieved due to low energy consumption for technological operations for cleaning them from adhered particles and lumps of clay. So, it is not required to create critical rotation speeds of the drums to clean the flow of sand and the flow of gravel in the cascade mixing mode, and it is possible to use drums of large diameter for the highest efficiency of the cleaning process and obtaining high-quality gravel and sand. The quality of cleaning in these modes of rotation of the drum and the supply of the starting material in a spiral along the axis of the drum while obtaining maximum performance is achieved by cutting and washing out pieces and washing off clay particles with directed jets of water on the visor of the cascade of material moving in the drum. At the same time, large expenditures are not required to create a high pressure of these jets due to their selective direction, when clay particles and lumps are opened from the mixture towards the water jets on the cascade canopy. When cleaning sand and gravel mixtures by known methods, this selective washout of clay is absent, and less effective surface irrigation of the mixture cascade with washout of clay is performed. An even greater effect of cleaning sand and gravel in a rotating drum occurs due to the elimination of dirty water with washed clay immediately through the sieves in the drum windows as it descends from top to bottom in a counterflow along the drum cavity, thereby reducing the degree of contamination of the mixture along the length of the drum and achieving complete cleaning her at the exit.

Known device for sorting and washing installation C - 213 for washing gravel from clay impurities, containing a drive and a main rotating drum with a washing section and two sorting sections, and a sorting drum covering the middle part of the main drum, mounted on a frame with the ability to adjust the angle of inclination to the line horizon, characterized in that the sorting drum is made with calibration holes, and the washing section is equipped with shelves for gravel capture, ring-shaped partitions - thresholds and a water conduit with a branch pipe installed along the axis of the section, with holes, and the main drum is equipped with a bandage and is made rotating on support rollers frames.

The disadvantage of the known device is the low quality of washing gravel from adhering lumps and clay particles, as well as low productivity in obtaining high-quality cleaned gravel.

The closest in technical essence to the proposed device is a device for sampling clay and cleaning gravel and sand, containing an electromechanical drive, a support frame with driving and driven rollers and a washing drum rotating on them, installed with the ability to adjust the rotation speed and angle of inclination to the longitudinal axis of the frame, made with floating rims and internal spirals, providing uniform loading and unloading of sand or gravel, devices for loading and unloading sand or gravel mixture, as well as a branch pipe with holes for water nozzles, mounted motionlessly inside the cavity of the drum and connected to a pressure water conduit.

The disadvantage of the known device is the low productivity of obtaining clean sand or gravel, poorly washed from lumps and particles of hard-to-wash clay, since there is a multidirectional water jets in the nozzle during self-lining of the drum with washing material. Contaminated water with washed clay, going down the drum from top to bottom, significantly contaminates the material supplied for washing at the outlet, not ensuring the quality of washing or reducing the productivity of the technological process with a high-quality washing mode.

The technical result of a device for sampling clay and cleaning gravel and sand, containing an electromechanical drive, a support frame with driving and driven rollers and a washing drum rotating on them, installed with the ability to regulate the rotation speed and angle of inclination to the longitudinal axis of the frame and made with floating tires and internal spirals providing uniform loading and unloading of sand or gravel, devices for loading and unloading sand or gravel mixtures, as well as a branch pipe with holes for water nozzles, installed motionlessly inside the cavity of the drum and connected to a pressure water conduit, is achieved by the fact that it is equipped with additional branch pipes with holes of water nozzles, and the nozzles are installed coaxially along the axis of rotation of the drum and are connected to each other with the possibility of relative coaxial angular displacement, and the water nozzles are arranged in a row, while windows with calibrated sieves are made on the inner cavity of the drum along the axis of rotation, and the mouth the unloading device is located at the upper end of the drum and is made in the form of a grate lattice nozzle fixedly connected to the frame, rolled into rings and covering the upper end of the drum, and also installed with a gap along the axis of the latter, and the drum spirals are made beyond the limits of the latter with the unloading side and rotating in the grating of the unloading device.

Figure 1 shows a diagram of a sorting and washing plant for sand and gravel mixture, figure 2 - the design of a device for extracting clay and cleaning gravel and sand, figure 3 - section A-A of figure 2, figure 4 - view B Fig. 2.

The mobile sorting and washing plant (Fig. 1) consists of a storage hopper 1 of a sand and gravel mixture, an adjustable gate 2 for feeding a mixture, an apron feeder 3 with a conveyor 4 for uniform supply of the mixture to a washing sorting sieve inertial screen 5 with trays 6 and 7, respectively feeding gravel and sand mixture with unwashed lumps and particles of hard-to-wash clay into washing drums 8 and 9, conveyors 10, 11 for unloading cleaned gravel and sand into dumps, electromechanical drives 12 with a control panel and a pumping station (not shown) with a pressure water conduit 13, trays 14 and 15 to drain the sludge into the sump.

The device for sampling clay and cleaning gravel and sand (figure 2) consists of a rotating drum 8 and 9 mounted on a support frame 17 with the ability to adjust the angle of inclination of the axis of its rotation relative to the longitudinal axis of the frame using screw jacks 18. The support frame 17 is equipped with leading 19 and driven 20 rollers interacting with floating drum tires 21 with the possibility of adjusting the speed of rotation of the latter. The drum 8, 9 from the lower end is equipped with a device 22 for loading gravel or sand mixture and at the upper end is equipped with a device 23 for unloading cleaned gravel or sand, as well as a chute 15 for removing clay sludge into sedimentation tanks. At the same time, spirals 24 are made on the inner surface of the drum, ensuring uniform movement of the mixture, loading and unloading gravel or sand, as well as technological windows with built-in calibration sieves 25. In the inner cavity of the drum 8, 9, pipes 26 are coaxially installed with a unidirectional row of holes 27 for water nozzles connected with each other and the pressure water conduit 28 with the possibility of relative coaxial displacement. The unloading device 23 (Figs. 2, 3) is fixedly connected to the frame 17 and is made in the form of a lattice nozzle, covering the upper end of the drum, from metal rods 29 rolled into rings and installed with a gap along the axis of rotation of the drum, and the spirals 24 of the drum extend beyond limits of the latter and made rotating in the lattice nozzle of the unloading device. The electromechanical drive 12 and a pumping station (not shown) ensure the normal operation of the mobile sorting and washing plant.

The method of sampling clay and cleaning gravel and sand in the proposed device is implemented as follows. The sand and gravel mixture sifted from the boulders from the body of the dump truck goes through the grate into the storage hopper 1 and dosed by means of an adjustable gate 2 is fed by the apron feeder 3 to the belt conveyor 4 and then to the sieve of the inertial screen 5, where it is subjected to intensive preliminary washing from clay particles and dirt, sifted and after separation into sand and gravel mixture in two streams flows through the corresponding trays 6 and 7 gravel and sand mixture into the loading devices of washing drums 8 and 9, rotating on tires 21 at a given frequency using an electromechanical drive 12 on support leading 19 and driven rollers 20 at an angle to the horizontal longitudinal axis of the frame 17, exposed by screw jacks 18. Spirals 24 on the inner surface of the drum 8, 9 provide uniform loading, transportation, washing and unloading of clean gravel and sand onto belt conveyors 10 and 11 into dumps. In this case, the washed particles and lumps of clay with water flow by gravity from the loading window of drums 8, 9 into trays 14 and 15 and are removed in the form of sludge into settling tanks 16. The mixture of gravel and sand transported in a countercurrent flow in drums 8 and 9 is mixed in a cascade mode and is subjected to intensive cutting and washing with water jets coming from the pumping station through the water line to the nozzles 26, connected to each other with the possibility of relative coaxial angular displacement, to the rows of holes 27 of the water nozzles directed to the upper ridge of the canopy of the mixed mixture cascade. In this case, the particles and lumps of clay that open from the mixture are intensively squeezed out and with water are guided by gravity along the drum to the trays 15, and as they move along the drum, clay particles with water and smaller particles of sand are additionally removed through calibrated sieves 25 in the drum windows, cleaned by water jets from the holes of 27 water nozzles. Washed gravel and sand from drums 8 and 9 is carried out by spirals 24 into the unloading device 23 and sieved through metal rods 29.

The proposed method and device make it easy to select the mode of high-quality washing of gravel and sand mixtures during their cascade mixing in rotating washing drums. In this case, it becomes possible to use the largest and most productive drum diameters. At high productivity, the quality of sampling of clay and cleaning of gravel and sand is ensured by the directed flow of a series of water jets (with insignificant energy consumption of the pumping station), striking and cutting the visor of the cascade of the mixing mixture, on the upper ridge of which lumps and clay particles are exposed. Technological windows with calibration sieves along the axis of the drum make it possible to immediately remove the clay from the drum, reducing the degree of contamination of the mixture at the outlet to the drum and allowing to enhance the process of intensive clay removal. A prototype of a mobile sorting and washing plant has been created and is successfully operating in the city of Torzhok, while the high performance of the device for producing clay from a mixture is combined with high quality cleaning of gravel and sand by the wet method in a cascade mode.

Sources of information taken into account when drafting the application

2. Book. V. V. Olyunin Processing of nonmetallic building materials. - M .: Nedra, - p. 189-190, fig. 69 (prototype by method).

3.L.A. Feigin. Crushing, sorting and conveying machines. / Training. for prep. workers on the pr-ve / Ed. 3rd, rev. and add. - M .: Higher school, 1977, - pp. 95-96 (analogous to the device).

4. V.V. Troitsky. Washing and de-sludging of minerals. - 2nd ed., Rev. and add. - M .: Nedra, 1988, - pp. 86-88 (device prototype).

CLAIM

1. A method for sampling and cleaning gravel and sand, including screening, separation of the mixture into two streams previously cleaned from clay particles, separate supply of each flow of gravel and a stream of sand for washing, unloading and transportation of cleaned gravel and sand to a dump and sludge to settling tanks, characterized by that the washing of the corresponding flow is carried out in a rotating drum, the mixture is fed along spiral paths in a cascade mixing mode, with the help of pressure jets of water directed to the cleaned flow of gravel or sand mixed in a rotating drum, while the water jets are supplied through the nozzles installed coaxially along the axis of rotation of the drum and interconnected with the possibility of relative coaxial angular displacement, the water nozzles of which are located in a row, and the washed particles and sludge, as well as crushed, pieces of clay are removed through the windows with calibrated sieves located along the length of the drum, the unloading of cleaned gravel or sand is carried out through an unloading device located on the upper end of the drum and made in the form of a grate lattice nozzle fixedly connected to the frame, made of metal rods rolled into rings and covering the upper end of the drum, and also installed with a gap along the axis of the latter, and the drum spirals are performed beyond the latter from the unloading side and rotating in lattice nozzle of the unloading device.

2. A device for sampling clay and cleaning gravel and sand, containing an electromechanical drive, a support frame with driving and driven rollers and a washing drum rotating on them, installed with the ability to adjust the rotation speed and angle of inclination to the longitudinal axis of the frame and made with floating tires and internal spirals that ensure uniform loading and unloading of sand or gravel, devices for loading and unloading sand or gravel mixtures, as well as a branch pipe with holes for water nozzles installed motionlessly inside the cavity of the drum and connected to a pressure water conduit, characterized in that it is equipped with additional branch pipes with holes for water nozzles, and all nozzles are installed coaxially along the axis of rotation of the drum and are connected to each other with the possibility of relative coaxial angular displacement, and the water nozzles are arranged in a row, while on the inner surface of the drum along the axis of rotation there are windows with calibrated sieves, and the device for discharging The bar is located at the upper end of the drum and is made in the form of a grate lattice nozzle fixedly connected to the frame, rolled into rings and covering the upper end of the drum, and also installed with a gap along the axis of the latter, and the drum spirals are made beyond the latter from the unloading side and rotating in the grid nozzle of the unloading device.

Washing of sand, gravel and water circulation. Solution overview

One of the important technological operations in the primary enrichment of ores and placers of precious metals or processing soils into building materials is washing, in the vast majority of implementations combined with sorting. And if for enrichment it is really important not to miss anything, having processed the entire volume of material, which is highly efficiently and highly efficiently solved by washing in drum screens (scrubber-butars), then for the tasks of obtaining future building materials it is easier to get rid of useless clay, earth and other inclusions at the earliest stage, so to speak, without waiting for the stage of deep processing. The latter is achievable when processing igneous rocks by the drilling and blasting method, when everything we do not need is concentrated in the quarry fines, and then it is quite enough to weed out the fines immediately after the feeder and send material larger than 40 mm for crushing, for example, and the fines to the dump or for reclamation. But there are a number of situations when flushing remains necessary or desirable (after all, nothing in our country is absolutely necessary):

high clay content in the original rock,
the rock is relatively fragile and is accompanied by clay (limestone, dolomite),
processing of ASG (sand and gravel mixture) or GMS (gravel and sand mixture) is carried out,
there is a desire to have high-quality sand and washed gravel.

In these cases, we must follow a much more complicated path than simply sifting out the little things, in which unwanted inclusions are really concentrated, clogging our future finished product (especially sand) and simply spoiling the properties of crushed stone (covering the surface) or technological equipment (covering the grids), what ultimately ends up spoiling the products of crushing and sorting, namely: washing the material.

Flushing can be organized in the following ways:

Washing sand and gravel in a drum screen (scrubber butare, trommel)

The scrubber-butara is an extremely simple mechanism, which is a drum (thrommel) with a blind part of the shell on the inlet side and blades inside and a perforated part on the outlet side. The drum rotates, material and water are fed into it, the blades entrain the material and mix it, while the material is irrigated with rinsing water. Mutual friction of the material in the water flow leads to the effective separation of dirt, clay, earth, plant and other small inclusions from the surface of the lump material. Getting further into the perforated part of the drum, the lump material that does not pass through the holes is separated from the water and all the fines 0-10 mm, which goes into the drain. Large material is unloaded for further processing. There are drums modifications in which there is a section with a shower at the output, which further improves the quality of cleaning the surface of lump material.

loading material of large size (up to 150 mm, and possibly larger);
high degree of surface cleaning due to friction and irrigation;
there is practically no self-grinding of lumpy material, that is, there is no effect on the granulometry of useful material;
high productivity for solid (up to 300 m3 / h with a drum size: diameter 3 m, length 10.5 m; drive power for rotation of about 90 kW);
the material is divided into large, medium (with a double perforated drum) and fines (drain, 0-10 mm).

large dimensions of the installation (despite the fact that for equipment with high productivity and efficiency and with a large feed size, the equipment can be called compact, but when drawing up the technological chain and to reduce the transporting equipment, the scrubber-butar is placed at a great height, which requires a long conveyor to load the initial and powerful frame);
the size of the holes of the perforated part of the drum is set during manufacture;
very high water consumption (up to 1000 m3 / h for maximum performance) - 3-3.5 parts of liquid per 1 part of solid;
subsequent dehydration of the washed material and discharge is required.

Coarse material with part of the water is most often sent to screening, during which the material is divided into different fractions. The smallest fraction accumulates the remaining water and is a pulp to be dehydrated as well as a drain from a drum screen. Effective border of separation of the drum screen into overflow and large: 5-10 mm.

Sand and gravel washing in a trough sink

A trough sink is, as you might guess, a tank (trough) with one or two shafts with blades. The reservoir is always filled with water, and the mixing paddles effectively clean the surface of the material.

loading medium-sized material (5-60 mm, maximum up to 100 mm);
work with any content of clay or other polluting inclusions;
high degree of surface cleaning due to direct exposure and mutual friction in water;
there is no self-grinding of lumpy material, that is, there is no effect on the granulometry of useful material.

there is no division into fractions (only washing) and even separation of the drain;
low solid performance at high power and comparable dimensions with a drum screen (up to 100 m3 / h with a unit size: shaft diameter with blades 1200 mm (x2), length up to 10.5 m; drive power for rotation is about 80 kW);
large installation dimensions;
high water consumption (up to 200 m3 / h for maximum productivity) - 2 parts of liquid per 1 part of solid;
subsequent dehydration of the washed material is required.

The material is fed mainly as wet or dry bulk material after the screen, but is discharged with water and requires dehydration and separation into fractions, at least to remove washed inclusions, as a result, there is no effective separation boundary between overflow and coarse.

Washing of sand and crushed stone in a complex screen with irrigation

A screen with sprinkling does not have a fundamental difference in design in comparison with a conventional screen, but in fact, a washing screen requires a better manufacturing, the use of steel with corrosion protection (stainless or special coatings). Irrigation is created using a system of nozzles installed above the screen, through which water is supplied to the upper screen and the material on it.

high feed size (up to 250 mm);
efficient separation into specified fractions determined by replaceable meshes;
sufficiently high-quality washing from dusty and clay inclusions;
relatively small dimensions with high solid performance (up to 300 m3 / h with an installation size (LxWxH) 8x3.5x5 m, drive power about 30 kW);
reasonable water consumption (up to 300-450 m3 / h at maximum performance) - 1-1.5 parts of water for 1 part of solid

high-quality washing only for a small content of clay inclusions and dust for crushed material;
subsequent sand washing and dehydration is required.

The effective size of the separation into a drain and a large one depends on the installed lower mesh and is in the range: 2-8 mm.

Spiral classifier (or dehydration wheel) rinsing

The spiral classifier is an inclined trough with an auger that lifts material from the bottom of the trough, where it is loaded, to the upper part, which is above the water level, ensuring the simultaneous separation of small particles and water going down the drain from large particles. Applies to sands only. There are models of spiral classifiers (called wheeled dehydrators), which in the horizontal trough, in addition to a screw or a spiral of small diameter, can have an even larger spiral that improves the movement of the material, and an exit wheel that works like a dredge with perforated buckets that remove sand from the water and unload it to the side (to the conveyor), which significantly improves dehydration - dehydration.

high productivity for solid material with dimensions comparable to that of a butar (up to 400 m3 / h with an installation size (LxWxH) of 15x6.7x4.5 m, drive power about 22 kW);
there is no water consumption (water comes with sand (in the form of a drain from a screen, for example), it is maintained at the required level, but no additional supply is required);
has the function of dehydration (dehydration);
high-quality cleaning of sand from clay and other small inclusions.

only suitable for sands (up to 8-10 mm);
low discharge capacity (and for water taken with sand, respectively - up to 55 m3 / h).

The effective separation boundary for drain and sand is about 0.16-0.8 mm. The spiral classifier in our country is usually used after the washing screen for sand cleaning and dewatering.

Comparing the above ways of organizing the flushing, it becomes clear that in the vast majority of tasks it is impossible to do with one piece of equipment listed. If we only have sand that we want to clean, then we really only need a spiral classifier, but if we have an ASG with a small amount of clay and an average required performance, or we just want to have washed crushed stone after crushing it (when the surface is covered with dust from crushing), then we will rather organize a washing process like this: first a heavy screen to separate the boulders (not needed after the crusher), then a washing screen to separate into fractions, then a spiral classifier for washing and dewatering the sand. If the clay content is larger and the gravel does not undergo proper cleaning on the screen, then the gravel fractions from the washing screen must be fed to a trough sink, and after that they are again divided into a drain with a trifle, which will go into the same spiral classifier, on a smaller washing screen , and on gravel that will go into the cone. And finally, with a high clay content, the scheme should include: a drum screen (scrubber-butar), a wash screen and a spiral classifier.

As it could be understood from the fact that the disadvantages of the first three types of equipment there is a need to dehydrate the material, and the spiral classifier has an advantage that it has this function, and is used in the above described variants of the schemes absolutely everywhere, an important operation when washing the material is the processing of the drain with sand. Something needs to be done with him. According to environmental standards, and indeed common sense, which often contradict economic viability, we cannot take water from a reservoir (or river) and dump it back as is, or we don’t have the right, and the like. The following schemes can help us in processing the drain and separating sand from it (although it may not be necessary for primary tasks):

dehydration wheel (spiral classifier) \u200b\u200bfollowed by sending the drain for cleaning;
a sand dehydration unit based on a hydrocyclone and a dewatering screen, followed by sending the drain for cleaning.

The work and performance of the dehydration wheel can be seen above in its description as a flushing agent called a spiral classifier.

Sand dehydration unit based on a hydrocyclone and a dewatering screen

The installation operates on a partially closed cyclic principle, and is a modular design. Its base is a reservoir, which receives the initial mixture of sand, inclusions and water, and the level in the reservoir is maintained within a certain range. In fact, the tank is needed to provide a certain concentration of the mixture, which the centrifugal pump is able to lift into the hydrocyclone. In a hydrocyclone (or in a double hydrocyclone), due to centrifugal forces, almost 100% of particles larger than 100 microns and 50-80% of particles larger than 60-80 microns are deposited, which are discharged from a cyclone onto a dehydrating (dehydration) screen in the form of a highly concentrated mixture under the hydrocyclone. Smaller particles (which should contain all clay particles and other inclusions), depending on the fine settings, partly fall into the coarse material (that is, go to the screen), partly (mainly) are carried away with the main volume of water from the hydrocyclone to the system that separates the flow (automatic valve adjustment) to the return to the tank and to the drain, which is sent to the water treatment system. The dewatering screen is a polyurethane sieve with rare openings (usually 0.3-1.5 mm), through which water effectively leaves and merges into the tank, and sand particles slide into the estrus and are unloaded onto the conveyor.

Consider this setup in comparison with a spiral classifier (dehydration wheel):

performs the role of washing equipment for sand (up to 8-10 mm);
comparable performance on solid with the same or even less occupied area;
very high discharge capacity (and for water taken with sand, up to 750 m3 / h);
the possibility of regulating the size of washed sand in lower limits;
the drain has the best degree of cleaning from large particles.

lower maximum productivity for solid and high energy consumption (up to 200 m3 / h, with dimensions (LxWxH) 2.2x5.7x7.5 m, the drive power of the pump and vibrators on the screen is about 96 kW);
device complexity.

With regard to dehydration, it is also possible to draw conclusions about in which cases a particular route is used. When working with a small volume of water (flushing screen, for example), a spiral classifier will suffice. But if the volume of water is large (high-performance flushing drum and rumble behind it), it is preferable to install with a hydrocyclone and a dewatering rumble, since the available spiral classifiers will not be able to take the required volume of water without reducing the quality of work, which manifests itself in entrainment with a large volume of water exceeding the standard flow rate for the spiral classifier, larger particles, which makes the discharge significantly more clogged, and the sand at the outlet is depleted (but with a larger modulus), that is, the effective separation boundary of the spiral classifier rises to 0.3-0.5 mm. Another point can also influence the choice of the type of dehydrator: the quality of the resulting sand and the permissible loss of fine sand fractions. This means that the spiral classifier is a “rough” tool when working with small fractions of sand (effective separation border 0.16-0.25 mm). This means that out of the total mass of a mixture of sand of various sizes and clay particles, up to 100% of particles larger than 0.16 mm-0.25 mm will go into the sand as a finished product, and a small fraction of particles 0.1-0.16 mm, clay particles and sand fractions of 0-0.16 mm will leave with water. For our current requirements for consumed sands, this is tolerable and even normal. A dehydration unit based on a hydrocyclone can be called a “thin” tool, since clay particles and a small part of fine sand fractions of 0.08-0.1 mm will go into the drain, that is, the loss of fine sand fractions is minimized. Such fine sand fractions are necessary in the production of responsible high-strength concrete products, but due to the extremely low consumption of such concrete we have a demand for such sand.

Water circulation

The water that goes to the drain with the finest fraction must be purified and returned to circulation (recycling). Water recycling can be organized as follows:

pool (settling pond) for sediment sediment from the water,
installation of clarification (thickening).

Both methods use the principle of sedimentation of particles in suspension in the discharge, under the action of gravity (sediment). The smaller the particles, the worse they settle, and our clay particles are concentrated in a fraction of 0-0.1 mm, so the process is extremely slow, and large areas require large areas.

Pool (settling pond)

The pool (settling pond) is filled with sediment to the maximum depth, and then it must be cleaned. For this, either work is stopped during cleaning (for example, in winter or spring), or for this purpose a second pool is made nearby, which they begin to actively exploit, and the first is drained (water is pumped into a new one, for example), then it must still dry, and then the accumulated new “soil” of the bottom is removed. A reservoir for clarified water can also be arranged next to the sump, from which water is supplied to the washing plant. The volume of the pools takes into account the fact that sedimentation only by gravity takes several days.

Lightening Installation

The installation is usually the main tank into which the drain is supplied, and the flocculant (a chemical reagent that significantly enhances the growth of loose flakes (flocculus) from particles distributed in the tank and coming in with the drain) is added automatically. The resulting flocculi are large enough to settle quickly. Thus, the top layer of water in the tank is sufficiently clean and drains into an adjacent tank, usually a smaller one, from which the water is fed back to the washing plants. The rotor near the bottom of the tank (can rise to the surface) actively mixes the sediment, which is removed through the mud pump from the tank. The clarification plant, processing up to 1,500 m3 / h of discharge, has an area of \u200b\u200babout 230 m2 (diameter 17 m, height 4 m, volume 920 m3) and an installed capacity of 6 kW. For comparison, a settling pond with a five-day supply for processing 400 m3 / h of discharge (and supplying the same volume for flushing) should have a volume of about 26 thousand m3 and a reservoir of purified water also with a five-day supply of about 31 thousand m3, which with the same an average depth of 4 m corresponds to areas of 6500 and 7750 m2.

To all of the above equipment, regardless of the chosen scheme, it is also necessary to add a pumping station for supplying water from the reservoir for flushing, which should consist of a powerful pump and preferably a backup pump and an automatic control unit for them, auxiliary pumps (by filling or vacuum pumps to eliminate air traffic jams). For the mentioned 400 m3 / h and sufficient pressure for transporting and lifting water to the required height, a pump with a power of 110 kW is required.

And finally, if it is clear in general terms what to do with the removed “soil” when cleaning the pool, then something still needs to be done with the dirt removed from the clarification unit in a continuous mode. You can adapt your own relatively small “pond” for it, in which it will accumulate and dry out, or you can end the chain in an environmentally correct way: by installing a press filter. By feeding our “mud” into it, at the exit we will have a very fine powder enriched with clay inclusions.

In conclusion, I would also like to note that working with water is possible only at a positive temperature, which means that in our climatic conditions, the construction of a crushing and screening plant in the open air entails a seasonal principle of operation or a change in technology for the cold period, or requires the use of lightweight building structures with heating for year-round operation. As we all understand, all this makes the final product extremely expensive.

http://sgm-eng.ru

There are many ways to clean up beach sand for a design project. Sift rocks and other debris, and clean up organic matter and silt. If you need sterile sand, try baking it in the oven for 45 minutes. To remove salt, you need to boil the sand in water and then strain it through a coffee filter. To prevent sand from entering the house after a trip to the beach, rinse all toys and other items before putting them into the car. A baby powder sprinkled on a napkin is perfect as a means to remove sand. If all of the above methods do not help, use a vacuum cleaner to get rid of sand in the house or in the car.

Steps

Preparing beach sand for a design project

Take twice as much sand as needed. Usually, a certain amount is lost during the cleaning process. Take twice as much sand from the beach as you need for the project. Now you will definitely have enough material and you will not have to worry that it will end at the most inopportune moment.

Sift the sand to remove rocks and other debris. Use an old colander or strainer to sift the sand out of rocks and debris. You can also make your own tulle and container filter. Lock the tulle on top of the container with a rubber band, and then sift the sand through the fabric directly into the container.

Get rid of organic residues and excess debris. The beach sand contains a huge amount of crumbled shells, microscopic organisms, silt and other small litter. Fill half a bucket with fresh water to wash all excess. Stir the water while gradually pouring the beach sand into the container. Continue stirring for a few minutes, then slowly drain the liquid.

Drain the water slowly so that too much sand does not go away with it.
Repeat the process until the water is completely clear.

Bake the sand to sterilize it. Washed sand can be baked so that it becomes completely clean. Drain as much water as possible and transfer to a baking sheet. Preheat the oven to 150 ° C and bake sand for 45 minutes to sanitize it.

Boil the sand to remove the salt. Pour beach sand into a large saucepan and add enough water to cover it completely. Heat the water until it boils, then lower the heat or add more water if too much has evaporated. Cook for a few minutes to dissolve all the salt, then remove the pan from the heat and use a large colander to collect the sand.
- Try attaching a coffee filter to the neck of a large can with an elastic band. The coffee filter will help to effectively separate the salt water from the sand. Proceed with caution when working with a hot pot and let the water cool down to a temperature safe to touch.
- First remove all the salt if you want to mix sand with paint, otherwise it will corrode the canvas or paper after a while.

Get rid of the sand after your trip to the beach

Place old sheets on the car seats and in the trunk. Care must be taken in advance to ensure that no sand gets into the nooks and crannies of the boot, otherwise you will have to put in a lot of effort in the future to thoroughly clean the car after a trip to the beach. Before spending the day on the sand, grab old sheets and cover all surfaces inside your car.
- Back home, gently remove the sheets from the car seats and hang them in the sun, and when the sheets are dry, shake them out and wash them.
When leaving the beach, wash off any sand that has adhered to objects. If there is a shower or taps with fresh water on the beach, wash the objects as thoroughly as possible to remove as much sand as possible before putting them into the car. Rinse your feet, chairs, toys, and other sand-stained objects under the shower. It is also advisable to take a shower, change beach clothes and store bathing clothes in plastic bags.

Use baby powder to remove sand from the skin. If there are no showers on the beach, or you simply have no desire to shower, use baby powder to get rid of the sand. Sprinkle baby powder on your legs, feet, hands, or any other sandy areas of your body, then pat dry with a towel.
- Baby powder works best on damp skin.
Hang your sand-stained items in your yard when you get home. Despite your best efforts, some of the sand will certainly end up in your house. Try not to bring beach towels, bags, or other items inside, especially if they are still wet. Instead, dry the utensils outside and then shake out the sand.

Content:

The aquarium is an entire ecosystem, and soil plays one of the main roles in its successful development. The most popular species has been and remains aquarium sand. Like any other soil, it is gradually colonized with beneficial microorganisms. By processing waste products of the inhabitants of the aquarium, they reduce their toxicity. The decorative function of the sandy soil is also undeniable - aquariums always look spectacular with it.

The benefits of sand

It creates the most natural conditions in the aquarium, close to natural.
Waste and dirt do not penetrate deep into the substrate, which prevents heavy contamination. For the same reason, sandy soil is fairly easy to clean.
The most fertile soil for aquarium plants forms in the sand. Also, plants are better strengthened by their roots behind sandy soil.
Certain types of fish prefer sand exclusively. In it, they spawn, burrow, and some even use silica sand to improve digestion.

Types of aquarium sand

If you decide to choose sand as a substrate, you should carefully study all the characteristics of different species.

River. It has been used in aquariums for a very long time. Contrary to popular belief about its harm, many aquarists call river sand almost the best. You can buy it at a pet store, or dial it yourself, using two sieves - to filter out particles that are not suitable in size.
Quartz. It is obtained by crushing white quartz. The main advantage of this type is resistance to chemical attack. Quartz sand is neutral: it does not affect the hardness of the water. Another plus is that it neutralizes harmful substances that can form in the aquarium, such as iron oxide and manganese.
White aragonite. This species is formed from fragments of mollusks and corals. But it is important to remember that such a soil affects the hardness of the water, so it is not suitable for fish who need soft water.
The black. It contains grains of magnetite, ilmenite and hematite. It is formed as a result of natural leaching of lighter rocks. This soil is good in that, like quartz sand, it does not affect the hardness of the water.
"Alive" or marine. It is mined in the coastal strip, often closer to coral reefs. Sea sand got its name because of mining technology: it is packed without drying, and as a result, it retains full microflora. This substrate is ideal for marine aquariums.

We comply with the requirements

In order for the sandy soil in the aquarium to perform its functions with one hundred percent efficiency, you need to remember several parameters.

The grains must be the same size. Otherwise, caking begins, at the bottom substances hazardous to the fish are formed - ammonia and hydrogen sulfide.
Choose a substrate with fractions of at least 1.5 millimeters in diameter. The smaller one interferes with oxygen exchange. Because of this, waste and particles of food cease to be processed, and the aquarium is quickly contaminated, and it has to be cleaned more often.
Sand in the aquarium should not affect water. As mentioned above, white sand is not suitable for fish living in water with low hardness due to its calcareous composition.
If you mine sand with your own hands, choose a clean body of water that does not get toxic plums and waste. River sand should not contain debris or other debris. Self-extracted soil should be especially thoroughly cleaned and washed to prepare for laying.
Do not get involved in colored sand. Undoubtedly, it looks very beautiful and impressive, and the dyes are used harmless. But some species, such as red and yellow, contain iron oxide, harmful to fish. Gradually washed out of the soil, the substance can cause the death of the inhabitants of the aquarium.
Decorative moment: they believe that white sand makes the fish less bright.

Sand preparation

The sandy substrate must be prepared for placement in the aquarium. Especially if you use do-it-yourself river or sea sand. With it, the risk of bringing in dangerous bacteria and other microorganisms is very high. White and quartz sand purchased at a pet store, it is better to process too.

First of all, the substrate must be washed. This will require a plastic bucket or deep basin. The effect will be better if you fill up the sand in portions - in time, of course, longer, but the quality of washing is higher. In the container, the substrate is carefully washed under running water. Stir the sand vigorously with your hands or a spatula. All this must be done until the water becomes clear.

Try not to clean the sand with household chemicals. Soil can absorb the substance, and it will be extremely difficult to wash it. But over time, in the aquarium, the product will begin to stand out in the water and can harm the fish. Instead of chemical treatment, it is better to turn to boiling or calcining the sand, which is quite realistic to carry out on your own.

You need to boil the soil for 15 minutes, stirring continuously. Sand is calcined in the oven: evenly distribute it on a baking sheet and leave for half an hour at centigrade temperature. Prepared sand is poured into the aquarium in layers of three to five centimeters, no more.

Sand mixtures, gravel and flint sands are a kind of blood of any kind of construction, from industrial facilities to private home construction. On the basis of sand, 99% of the main building mixtures and fillers are prepared. The use of mixtures of an improved structure makes it possible to achieve higher quality without special costs. These materials include seeded, washed and chopped sand.

Gradation of sand masses

Construction grades of sands, in contrast to optical, quartz and mother sands, are not particularly pure, they have a huge amount of impurities in the form of clay and organic matter. It is clear that the degree of contamination significantly affected the quality of concrete or masonry mortar. The volume of construction has always been large, it was expensive to carry out special preparation and processing of sandy material, therefore GOSTs for construction raw materials, for example, GOST No. 8736-93, simply divided sand into three categories:

Large material - with a grain size of 2.8-5 mm;
Medium sand, with grains of sand 2.0-2.8 mm;
Fine screenings or sand seeded on a sieve with a mesh size of 2 mm.

For your information! In addition to size, regulatory documents determined the presence of contamination - no more than 0.03%, and the radioactive background of the sand mass. Other characteristics for the selection of high-quality sand for certain types of work did not exist, as there are no standards for water or clay.

The traditional method of separating dry sand mass on a sieve allows only qualitatively dividing the sand mass into size groups, removing organics, salts of iron, magnesium, aluminum oxides contained in sand is practically impossible.

Which sand is better

In practice, the quality and suitability of sandy material is traditionally determined not by the exact parameters of the mixture, but by the size and method of extraction. So, coarse sand is best suited for concrete castings of large thickness, medium sands are used for masonry mortar, and fine sandy loams are used as loosening additives in the production of certain types of building materials, for example, silicate blocks.

Washed quarry and river raw

The second determining criterion is the method of extraction of the sand mass. It is believed that washed river sand remains the best option for construction work. The sand material extracted from the bottom of the river and washed with a hydraulic seal has a high quality factor, uniformity and purity. Such pleasure is quite expensive, but the demand for such material is so great that washed river sand is sold in bags for 100-140 rubles per bag. Washed sand in bags is taken for household needs, for filling children's sandboxes, for small construction work and household purposes. Due to the high demand, merchants have adapted to wash and sell ordinary quarry material in bags, offering it like washed river sand.

To distinguish coarse-grained river sand from the quarry mass is quite simple - in the shape and size of grains of sand. River material washed and run in with water will have a more rounded shape, it is stronger and more flexible in concrete. The crater sand looks more kinky and dirtier.

The river sand will be white and clean, quarry, even washed and treated with chemistry, will retain a reddish or gray shade of iron and aluminum salts.

The second highest quality is washed quarry sand. The main disadvantage of quarry sandy material is the presence of a large amount of clay and organic salts. When mining the quarry mass, water cannons are used, which wash away the sandy layers into special sedimentation tanks, the clay and mud are filtered, and they get washed sand, more or less stable in quality.

To obtain washed coarse-grained material, the cleanest parts of the open-pit seam are produced with excavator equipment, loaded and sent to preparatory stations, where they are subjected to the following processing:

In air cyclones, sand is dried and separated by weight;
The most purified part is selected from the large fractions;
Rinsing with reverse water.

After drying, this sand is offered for sale in bags as a calibrated and washed sandpit.

For your information! For sand masses used for the construction of critical facilities, coarse sands can be activated by chemical reagents that increase the surface area of \u200b\u200bthe sand grains.

Therefore, if you need clean sand for your home, it is best to buy washed, uncooked material, which, firstly, will be cheaper, and secondly, will be guaranteed to be clean from surfactant additives and protectants.

The secret of washed sand

To obtain high-quality sand washed from a quarry technically does not pose a particular problem, the question rests on the stability of the characteristics of the raw material. Any sand quarry that produces large-scale commercial sand is usually layered material with different characteristics, which requires regular equipment changeovers and makes cleaning expensive. Washed river sand even after simple washing with water has a minimal amount of salts deposited on the surface of grains of sand.

Even in the presence of residual organic matter from silt and substances found in river water, washed river sand sticks much better with cement grains of concrete than even a chemically etched marine mixture.

The sandy mass extracted from sea water is considered the least suitable for use in construction, road construction, and even landscape design. The calcite nature of such a material leads to partial dissolution in concrete mixtures, and with prolonged interaction with acidic components it greatly loses in mass.

Conclusion

One of the most interesting types of sand masses is thermally processed sand mixture. In such washed sand, the bulk of the grains of sand has the shape of elongated sharp chips and needles, due to which the finished mixture gets high adhesion to practically smooth concrete surfaces. Such fillers are widely used in various deep penetration primers.