RU2268314C1 - Method of briquetting floatation fluorite concentrates - Google Patents

Abstract

FIELD: lumping of ground products, floatation fluorite concentrates in particular.

SUBSTANCE: proposed method includes mixing the fluorite concentrate with composite binder and mixture thus formed is molded at room temperature. Used as composite binder is molasses, unslaked lime of size 0.15 mm and water which are mixed preliminarily in reservoir for 1-5 min at weight ratio of 0.8-1.2:1:0.2. Moisture content of starting floatation concentrate reaches 12% and amount of composite binder ranges from 2 to 6% of mass of concentrate.

EFFECT: obtaining briquettes of high moisture resistance; possibility of keeping briquettes intact in the course of storage.

1 tbl, 1 ex

Description

The present invention relates to the field of agglomeration of crushed products, in particular flotation fluorite concentrates, and can be used for briquetting of powder products.

A number of methods are known for producing agglomerated material from flotation fluorite concentrate. For example, at the Kalanguisk fluorspar plant, the fluorite flotation concentrate was smelted by pelletizing a mixture consisting of flotation concentrate and bentonite, followed by firing at a temperature of 1000-1050 ° С and cooling. Instead of bentonite, it is known to use technical lignosulfonates. In autosvid. USSR No. 845318 "Method for granulation of fluorspar", a pelletizing method using low-modulus liquid glass and soda as a binder mixture in a ratio of 5: 1, followed by firing the granules at a temperature of 780-820 ° C. The work [Schedel A. "Stahl und Eisen", 1963, No. 83, s.207-217] indicates the possibility of producing pellets from a fluorite concentrate using sodium silicate as a binder. Pellets obtained in disk granulators were fired at a temperature of 370-400 ° C.

The main disadvantage of the noted methods of rolling flotation fluorite concentrates was the high energy costs and difficult sanitary and hygienic working conditions, therefore, these methods are practically not used at present. No less energy-intensive is the method of thermal melting of fluorite concentrate at temperatures up to 1300 ° С followed by cooling of the melt, proposed in the work of A.M. Shevyakov (MNTU "Optoelectronnauchpribor" report, authored A.M. Shevyakov, L., 1990) .

More progressive is the method of temperature-free briquetting of flotation fluorite concentrates with the addition of binders. So, in French patent 22666.71, published in the journal "Inventions Abroad" No. 23 on December 5, 1973, it is proposed to use sodium silicate (1-6 wt.%) And slag Portland cement (1-5 wt.%) Or lime-slag as binders cement (1-5 wt.%). In US patent 3871869 "Method for pressing briquettes from powder substances, in particular, from fine-grained fluorite", publ. in “Inventory Abroad,” issue 21, No. 8, 1975, as a binder, it is proposed to use a mixture of molasses (molasses) (0.5-6 wt.%) and cement (0.6-5 wt.%) . In studies on the briquetting of fluorite flotation concentrate of the Burundur deposit (Mongolia), performed at the Institute of Metallurgical Ceramics (Bratislava), the following substances were used as binders: dry residues of sulphite-alcohol stillage, liquid glass (sodium silicate), bentonite, milk of lime, Portland cement, hexamethyl cellulose. The pressing pressure was (about 50-60 MPa), the best results were obtained with liquid glass at a flow rate of 60 kg per ton of concentrate (I. Bulander Report on the pilot production of fluorite briquettes at the Vitoshov plant (Ore mines, Esenik enterprise), carried out in August September 1989, Prague, Intergeo, 1990). Similar results were obtained when using Sibtsvetmetniiproekt as a liquid water binder in the Institute (report "Finalization of the technological procedure and briquetting technology for fluorite concentrates of the Yaroslavl GOK". V.I. Adamovich, E.A. Kochetkova, S.N. Kiseleva. Sibtsvetmetniiproekt. Krasnoyarsk, 1991).

The main disadvantages of the method of briquetting using liquid glass, cements is the relatively high cost of these products, as well as the presence of silicon oxide in their composition, the content of which is limited in fluorite briquettes. In addition, briquettes obtained with liquid glass require for their hardening low-temperature drying at 150-200 ° C. A number of binders of a similar type are given in the work of LB Khoroshavin, II Ovchinnikov and others (Non-ferrous metallurgy, No. 12, pp. 39-42, 2002).

There are a number of methods for briquetting flotation spar flotation concentrates, in which a mixture of lime-fluff fluff (slaked lime) and molasses (molasses), taken on the basis of dry weight in a ratio of 1: 1, followed by pressing briquettes (US patent 4139587 13.02. 1979, С 22 В 1/08, С 21 С 7/00, book "Briquetting of ores", Ravich B.M., Moscow: Nedra, 1982, pp. 63-64).

The disadvantage of these methods is the insufficient strength of the briquettes under conditions of multiple overloads and susceptibility to moisture.

The closest in technical essence and the achieved result to the present invention is a method for producing briquettes from finely ground fluorspar, comprising mixing a fine-grained concentrate with a combined binder, which is used as a mixture of lime-fluff fluff and molasses (molasses), taken on the basis of dry weight in the ratio 1: 1, the subsequent pressing of the mixture at normal (room) temperature, with the molasses being mixed in a state heated to 50 ° C, and the solid content in it was It is 58-70%. A mixture of lime-fluff and molasses is introduced in an amount of 5-11% by weight of the concentrate, the resulting briquettes are then aged in vivo (RF patent 2205235 from 2003.05.27). The disadvantage of this method of briquetting is the need to use dry flotation concentrate resulting from expensive drying after filtration. Use as a binder lime-fluff (slaked lime) is a prerequisite for this method of briquetting. At the same time, many enrichment plants (including Yaroslavl GOK OJSC) produce quicklime (CaO) for their own needs. However, the use of quicklime in the known methods of briquetting in the presence of molasses (and without it) leads to the destruction of the briquettes during their storage due to the transition of quicklime to calcium carbonate.

In addition, the high consumption of binders (5-10% by weight of flotation concentrate) leads to an increase in the cost of briquettes, the cost of which should not exceed the cost of lump fluorite concentrate (so, the cost of FC-75 currently does not exceed 65-70 US dollars per 1 t).

The goal is to obtain briquettes from fine-grained fluorite concentrate in the present invention is achieved in that, in contrast to the known method for producing briquettes from finely ground fluorspar, comprising mixing fine-grained concentrate with a combined binder, consisting of a mixture of lime-fluff and melasse heated to 50 ° C (in which the solids content is 58-70%), taken on the basis of dry weight in a ratio of 1: 1, and subsequent pressing at normal (room) temperature, is used in As a binder syrup, quicklime with a particle size of 0.15 mm, pre-mixed for 1-5 minutes in a separate container when water is supplied to the binder in a mass ratio of 0.8-1.2: 1: 0.2, while the moisture content of the original flotation concentrate can be up to 12%.

The optimal consumption of a pre-prepared mixture of quicklime, molasses and water, comprising 2-6% by weight of the concentrate, and the ratio by weight in the mixture of molasses to quicklime and water is 1: 1: 0.2, and the humidity of the initial concentrate is 0.1- 12% were established by preliminary studies (Table 1). The mixing time of binders - quicklime, molasses and water was also chosen experimentally. When the moisture content of the initial fluorite concentrate exceeds 12%, briquettes are destroyed due to sticking of the press cells. After pressing, the briquettes are aged for ripening for 4-5 days.

Pre-mixing quicklime, molasses and water in a ratio of 0.8-1.2: 1: 0.2, apparently, leads to the formation of compounds of the type:

which allows to avoid the destruction of briquettes during their storage, increases the resistance of briquettes to moisture.

The invention is illustrated by the following example.

The initial flotation fluorite concentrate obtained at OAO Yaroslavl GOK contains 90-92% CaF ₂ and has a particle size of 100% cells. - 50 microns. For the needs of ferrous metallurgy, briquettes with a particle size of more than 25 mm are required, which must have a crushing resistance of more than 80 kgf per briquette, withstand more than 8 drops on a concrete floor until it collapses. It is desirable that the briquettes were moisture resistant during transportation to the consumer. For this, a concentrate containing from 12% moisture (filter cake) to 0% moisture (dried concentrate) was mixed with a mixture of binders: quicklime with an activity of 60-70% produced by Yaroslavsky GOK, pre-crushed to a particle size of 0.15 mm , molasses and water, prepared in a separate mixer with stirring for 1-5 minutes, and then sent to continuous pressing with a roller press. The results of these studies are shown in table 1. The briquettes obtained in optimal mode from flotation fluorite concentrate were studied by a potential consumer of Mechel Chelyabinsk Plant, which issued a positive opinion on this type of product.

It should be noted higher moisture resistance of briquettes obtained by the proposed briquetting method compared to the prototype, because they retain their shape when stored in water for 24 hours.

Table 1
The quality of fluorite briquettes obtained by various methods of preparing flotation fluorite concentrates for briquetting No. p / p Pressing Pressure, MPa The composition of the charge,% The quality of fluorite briquettes (after 5 days of ripening) flotation fluorite concentrate Water (moisture concentrate) Mixture (molasses: lime, solid water) Separate feed crush resistance, kgf / briquette The number of briquettes falling onto a concrete floor (2.0 m) before destruction Sustainability in water (24 hours storage) Quicklime Syrup one. twenty one hundred 0.1 2 (1.2: 1: 0.2) - - one hundred 12 retains shape twenty one hundred 0.1 3 (1.2: 1: 0.2) - - 125 <20 retains shape twenty one hundred 0.1 6 (1.2: 1: 0.2) - - 125 <20 retains shape twenty one hundred 0.1 - 2 four briquette breaking retains shape After 1 hour 2. 60 one hundred 0.1 2 (1.2: 1: 0.2) - - 105 fourteen retains shape 60 one hundred 0.1 3 (1.2: 1: 0.2) - - 125 <20 saves

No. p / p Pressing Pressure, MPa The composition of the charge,% The quality of fluorite briquettes (after 5 days of ripening) flotation fluorite concentrate Water (moisture concentrate) Mixture (molasses: lime, solid water) Separate feed crush resistance, kgf / briquette The number of briquettes falling onto a concrete floor (2.0 m) before destruction Sustainability in water (24 hours storage) Quicklime Syrup 60 one hundred 0.1 6 (1.2: 1: 0.2) - - 125 <20 keeps the form 60 one hundred 0.1 - 2 four destruction of briquettes after 1 hour shape keeps shape 3. twenty one hundred 0.1 2 (1.2: 1: 0.2) - - one hundred 12 retains shape twenty one hundred 0.1 3 (1: 1: 0.2) - - 125 <20 retains shape twenty one hundred 0.1 6 (1: 1: 0.2) - - 125 <20 retains shape twenty one hundred 0.1 - 2 3 destruction of briquettes after 1 hour retains shape four. twenty one hundred 0.1 3 (0.8: 1: 0.2) - - 110 12 retains shape twenty one hundred 0.1 6 (0.8: 1: 0.2) - - 125 <20 retains shape 60 one hundred 0.1 6 (0.8: 1: 0.2) - - 125 <20 retains shape 60 one hundred 0.1 - 2 2,5 destruction of briquettes after 1 hour retains shape 5. twenty one hundred 8 3 (1.2: 1: 0.2) - - 110 12 retains shape twenty one hundred 8 6 (1.2: 1: 0.2) - - 125 <20 retains shape twenty one hundred 8 - 2 four one hundred 8 retains shape 6. twenty one hundred 12 3 (1.2: 1: 0.2) - - 110 12 retains shape twenty one hundred 12 6 (1.2: 1: 0.2) - - 125 <20 retains shape 60 one hundred 12 3 (1.2: 1: 0.2) - - 110 fifteen retains shape 60 one hundred 12 6 (1.2: 1: 0.2) - - 125 <20 retains shape 60 one hundred 12 - 2 four one hundred 8 retains shape 7. twenty one hundred 14.0 3 (1.2: 1) - - briquetting failure 60 one hundred 14.0 6 (1.2: 1) - - briquetting failure 60 one hundred fourteen - 2 four briquetting failure

Claims (1)

A method for briquetting flotation fluorite concentrate, comprising mixing a flotation concentrate with a combined binder containing molasses as one of the components, and then pressing the mixture at room temperature, characterized in that the combined binder contains molasses, quicklime with a particle size of 0.15 mm and water by weight the ratio of 0.8-1.2: 1: 0.2, which are pre-mixed for 1-5 minutes, while the humidity of the initial flotation concentrate is up to 12%, and the number of comb the binder is 2-6% by weight of the concentrate.