RU2628971C1 - Quartz sand enrichment device - Google Patents

Abstract

FIELD: machine engineering.

SUBSTANCE: device for enrichment of quartz sand comprsises a supply hopper for unenriched quartz sand which is equipped with a discharge feeder, a lifting-and-transporting mechanism supplying unenriched quartz sand from the supply hopper to the input of a vibrating screen, a magnetic separator which input is connected to the under screen output of the vibrating screen, and the output is connected to the hopper for enriched quartz sand, and a hopper for oversized quartz sand. The device is additionaly provided with a reverse feeder for discharging the hopper with oversized quartz sand and a flow switch which input is connected to the above sceen output of the vibrating screen. The first output of the flow switch is connected to the input of the lifting-and-transporting mechanism. The second output of the flow switch is connected to the oversized quartz sand hopper connected by its output to the input of the reverse discharge feeder, the first output of which is connected to the input of the lifting-and-transporting mechanism, and loading of oversized material for disposing is carried out from the second output.

EFFECT: reduction of quartz sand losses.

3 dwg

Description

The invention relates to techniques for the enrichment of dry quartz sand, supplied to glass factories by road and rail, and can be used to enrich various bulk materials in the construction, chemical and other industries.

Quartz sand used for the production of glass blends is used in glass factories either in the form of conditioned raw materials that do not require deep processing and enrichment, or in the form of material that must be additionally dried, sieved and separated directly in the compound workshops of these enterprises. In both cases, in the production of colorless glass containers and colorless sheet glass from quartz sand, it is necessary to remove not only sand particles larger than 0.63-0.8 mm, but also iron-containing impurities. To do this, the sand is dried if it has a moisture content of more than 0.5-1%, graded according to particle size distribution using sieves, screens and other devices, as well as subjected to magnetic separation to increase the grade of sand and the release of highly magnetic and weakly magnetic inclusions from it.

Since quartz sand is supplied dry to glass factories, it does not require additional drying in drying drums or in vibro-boiling layer plants. But, given the fact that such sand is often shipped to wagons in which other bulk and small-sized materials (such as crushed stone) are transported, quartz sand may be contaminated with impurities. These impurities must be removed by sieving on polygonal screens, vibrating screens and other technological units. During sifting on the screen, depending on the technological requirements and the size of the sieving holes, particles of increased particle size are separated from the sand, which are constantly sent to the corresponding sowing bin. But at the same time, along with screenings, conditioned sand with particles of a given particle size distribution also gets into the screening bin. This is explained by the fact that in case of partial clogging (clogging) of the mesh openings, the oversize product from the lower layers of the sand thickness shields and blocks the complete sieving of the overlying layers of sifted sand, the loss of which in this case can be 200-300 kg or more when unloading only one hopper car . The total daily loss of conditioned sand sent to the dump for large-scale production of flat glass is measured in several tons. At the same time, the number of screenings of the coarse sand fraction and foreign inclusions can be significantly less than these losses of conditioned raw materials. Therefore, it is necessary either to reduce the productivity of the sifting operation, which increases the downtime of the cars during their simultaneous unloading, combined with the sifting of quartz sand, or to increase the area of the sieving mesh and constantly monitor the degree of clogging, which is not always possible.

A known scheme for the enrichment of quartz sand [1], containing a compartment for storing sand discharged from wagons, a clamshell crane, a receiving hopper with an unloading feeder, a drying drum, a lifting and transport mechanism, a sieve, a hopper for sifted dry sand and a hopper for screening the coarse fraction of material and foreign inclusions . The disadvantage of this scheme is the lack of magnetic separation of quartz sand and the partial removal of the conditioned material into the screening hopper along with the oversize product.

The closest technical solution to the claimed one is a scheme for the enrichment of quartz sand [2], consisting of a receiving hopper with an unloading feeder, a drying drum, a conveyor belt, a sieve, a hoisting-and-transport mechanism in the form of a bucket elevator, a magnetic separator and a silo of enriched quartz sand. This scheme allows you to additionally remove iron-containing impurities from the sand being enriched, which subsequently significantly improves the quality of colorless glass melt. But just like in other well-known solutions, in this line the losses of dry sifted sand falling into the screening hopper from the sieve along with the oversize product are not excluded.

Such disadvantages are inherent in most of the processing lines for enriching both dry and wet quartz sand and are usually associated with clogging of the sifting holes of the grids of the classification aggregates during the continuous enrichment process, during which accumulated impurities must be periodically removed from the screener for further disposal. At the same time, screening of screening holes of grids often occurs when silica sand is delivered to glassworks from different concentration plants, since sand particles of different deposits have different shapes. The same disadvantages are also characteristic of batch lines in which the dry quartz sand is enriched in the process of unloading and further transportation of the raw material delivered to the compound workshop in railway cars or by road. Similar disadvantages exist in the sand screening lines, in which the screened material is periodically transported from large-capacity storage silos to the suspended weighing hoppers of metering and mixing lines.

The problem to be solved is the reduction of losses of dry quartz sand during its enrichment in batch lines.

The specified technical result is achieved by the fact that the device for enriching quartz sand, consisting of a feed hopper of unenriched quartz sand, equipped with an unloading feeder, a lifting and conveying mechanism that feeds unenriched quartz sand from a feed hopper to the input of a vibrating sieve, a magnetic separator, the input of which is connected to the under-sieve the output of the vibrating sieve, and the output is connected to the bunker of enriched quartz sand, and the bunker of screenings of quartz sand, is additionally equipped with a reverse an external feeder for unloading the quartz sand screening hopper and a flow switch, the input of which is connected to the over-sieve output of the vibrating sieve, the first output of the flow switch being connected to the input of the hoisting-and-transport mechanism, and the second output of the flow switch connected to the silo of screening quartz sand the input of the reversing discharge feeder, the first output of which is connected to the input of the lifting and transport mechanism, and the screenings are shipped from the second output for disposal.

The difference between this technical solution and the prior art is the presence of a flow switch, the input of which is connected to the over-sieve output of the vibrating sieve. Moreover, the first output of the flow switch is connected to the input of the lifting and transport mechanism, and the second output is connected to the silo of screenings of quartz sand. The presence of a flow switch allows, with a slight contamination of the dry quartz sand discharged from wagons or motor vehicles, to sift it without constant discharge of coarsened fractions and foreign impurities from the over-sieve exit of the vibrating sieve. At the initial stage of sifting, which is carried out during the unloading of the entire batch of sand from the wagon or car, screenings and portions of quartz sand captured by them circulate along the line: over-sieve output of the vibrating sieve - input of the flow switch - first output of the flow switch - input of the lifting gear - input vibrating sieve. Screenings are not reset to the screener at this stage.

Upon completion of unloading and sieving of the entire batch of raw materials, screenings during two to four circulation cycles (the number of cycles may vary depending on the amount of impurities in the sand) continue to be additionally sieved through the indicated chain. During this additional screening, quartz sand is separated from the waste, after which the flow switch is switched and the waste, cleaned from sand, is sent through the second output of the switch to the screening hopper. This provides a reduction in the loss of dry quartz sand during its enrichment in the composite workshops of glass plants.

Another difference is that with increased clogging of the feedstock or an increased tendency to clog the openings of the vibrating sieve mesh with sifted quartz sand particles, multiple screenings of sand during sifting of the main unloaded mass of raw materials are not performed. In this case, screenings with a partial portion of the useful product during the entire cycle of unloading and enrichment are sent by a flow switch to the silo of screenings of quartz sand. And at the end of the unloading of raw materials from the carriage or motor vehicle, the reversible unloading feeder sends screenings with a portion of the useful product from the screener to the input of the lifting and transport mechanism. Since the additional sifting of the waste accumulated in this bin during the recycling process is performed with lower productivity, the useful product is more effectively separated from them, which also reduces the loss of quartz sand.

The principle of operation is illustrated by drawings, in FIG. 1 which shows a diagram of a device in the mode of recirculation of a small amount of waste; in FIG. 2 shows a diagram of a device in the recirculation mode of an increased amount of waste; in FIG. 3 shows a diagram of the shipment of waste for disposal.

A device for enriching silica sand comprises: a feed hopper 1 of unenriched silica sand equipped with a discharge feeder 2; hoisting and transport mechanism 3; vibration sieve 4; magnetic separator 5; silo 6 enriched silica sand; flow switch 7; bunker 8 screenings of quartz sand and a reversing feeder 9 unloading bunker screenings of quartz sand. The feed hopper 1 is loaded with unenriched quartz sand from a hopper car 10 or from a motor vehicle (not shown). Screening of quartz sand screenings for disposal is carried out using a reversing feeder 9 unloading in the car body 11.

The device operates as follows. The dry quartz sand discharged from the carriage 10 of the hopper type (Fig. 1) flows by gravity into the feed hopper 1, equipped with an unloading feeder 2, made in the form of a conveyor belt. Further, in the process of unloading the wagon (similar unloading from the car is possible), sand is transported to the inlet of the vibrating sieve 4 by means of a lifting and transport mechanism 3, which can be used as a bucket belt elevator 4. The vibrating sieve 4 (drum sieves can also be used) is equipped with a net the cell size of which is specified by the technological requirements for the granulometry of the enriched quartz sand used for glass melting. The sublattice product (sand that passed through the grid) from the vibrating sieve 4 enters the inlet of the magnetic separator 5, which separates iron-containing impurities from the enriched quartz sand. Sand without these impurities after the magnetic separator 5 is sent to the silo 6 of enriched quartz sand, and all iron-containing inclusions are poured into a small container or big bag (not shown in the diagram).

An oversize product containing extraneous inclusions larger than the mesh size of the vibrating sieve 4, as well as part of the useful product in the form of sand particles that did not pass through the mesh during sieving, from the oversize output of the vibrating sieve 4 is fed to the input of the flow switch 7. The ingress into the oversize product of a part of quartz sand with the granulometry required for glass melting is often due to the shielding of the upper layers of the screened material by its lower layers in direct contact with the grid. This occurs either at an increased feed rate to the input of the vibrating sieve of the sifted material, or when the mesh holes are partially clogged. Therefore, if the oversize product, consisting of aggregated particles, other foreign inclusions, as well as part of the useful raw material, is immediately dumped into the hopper 8 screenings of quartz sand, when disposing of the screenings there will be noticeable losses of conditioned quartz sand.

With a small number of aggregated fractions and other extraneous inclusions (stones, branches, film, etc.), it is possible in the process of sifting sand coming into this device when unloading, for example, one car, not to drop screenings into the hopper 8 screenings of quartz sand throughout the operation sifting of quartz sand, the volume of which is limited by the volume of the car. In this case, the screenings through the first output of the flow switch 7 are repeatedly fed to the input of the hoisting-and-transport mechanism 3 and circulate through the chain “hoisting-and-transport mechanism 3 - vibrating sieve 4 - input of the flow switch 7 - the first output of the flow switch 7 - hoisting-and-transport mechanism 3 »Until the end of sifting of the bulk of quartz sand. At the end of this operation, sand screenings are transported for several more cycles along this chain, during which a portion of quartz sand that has got into the screenings during the screening of the bulk of the raw material is finally sieved. This additional screening of sand screenings does not reduce the overall unloading capacity of the cars and does not lead to their additional downtime, since it is carried out during the supply of the next car to the unloading position when pushing the train.

Then, at the command of the control system (not shown), the switch 7 is switched, and the screenings cleaned from quartz sand through the second output of the flow switch 7 are sent to the silo sand screening hopper 8.

With a high content of impurities in the enriched quartz sand, the flow switch 7 remains in a position in which its second outlet is connected to the silo 8 screenings of quartz sand. In this case, sand screenings, including some of the conditioned quartz sand involved in screenings, are constantly discharged during sifting of a batch of material discharged from the car into the silo of 8 screenings of quartz sand. At the end of the unloading of the wagon, when another wagon begins to be installed at the unloading position, there is a time interval free from the main screening (2-3 minutes) during which additional screening of sand screenings can be carried out. Depending on the filling of the hopper 8, additional screening can also be performed after unloading several wagons. A similar operation is performed as follows.

The reversible feeder 9 for unloading the silica sand screening hopper by the command of a control system (not shown) is turned on so that its conveyor belt starts moving towards the first output of the feeder associated with the input of the lifting and transport mechanism (Fig. 2). Sand screenings are then unloaded from hopper 8 and fed to additional screening along the chain “hopper 8 — input of the reversing feeder 9 — first output of the reversing feeder 9 — input of the lifting-transport mechanism 3 — vibrating sieve 4 — input of the switch 7 of the flow — second output of the switch 7 flow - hopper 8 screenings. " The number of recirculation cycles of these screenings and the performance of the reversible discharge feeder 9 is regulated depending on the total number of screenings accumulated in the hopper 8.

Additionally sifted screenings as they accumulate are unloaded into road transport 11 (Fig. 3) and taken away for disposal. To do this, the direction of movement of the tape of the reversing feeder 9 is switched and the accumulated screenings from the second output of this mechanism are reloaded into the car body.

Thus, the additional presence of a flow switch and a reversible unloading feeder for the silica sand screening hopper allows additional screening of the screening of silica sand discharged from the cars without reducing the overall discharge performance, which reduces the loss of a useful product.

Information sources

1. Chemical technology of glass and glass. Textbook for universities, edited by N.M. Pavlushkina. M. Stroyizdat. 1983, p. 96-97.

2. Lozin A.A., Kubay L.V., Nityagovsky V.V. The use of magnetic separators in the glass industry // Glass containers. 2008. No8. S. 34-40.

Claims (1)

A device for the enrichment of quartz sand, consisting of a feed hopper of unenriched quartz sand, equipped with an unloading feeder, a lifting and conveying mechanism that feeds unenriched quartz sand from a feed hopper to the input of the vibrating sieve, a magnetic separator, the input of which is connected to the sub-sieve output of the vibrating sieve, and the output is connected to the silo of enriched quartz sand, and the silo of screenings of quartz sand, characterized in that it is additionally equipped with a reversing feeder unloading bu kera of quartz sand screenings and a flow switch, the input of which is connected to the over-sieve output of the vibrating sieve, while the first output of the flow switch is connected to the input of the lifting and transport mechanism, and the second output of the flow switch is connected to the silo of screenings of quartz sand, connected with its output to the input of the reversing feeder unloading, the first output of which is connected to the input of the hoisting-and-transport mechanism, and from the second output the screenings for disposal are shipped.

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