SU1546163A1 - Method of flotation of coal - Google Patents

Abstract

This invention relates to the enrichment of minerals by flotation in coal preparation plants. The goal is to increase the extraction of combustible mass in the concentrate, increase the selectivity of the process of coal flotation. The starting material is pulped and conditioned to a slurry with a silicon-containing reagent. As the latter, bis- (trimethylsiloxy) hexane of the formula (CH ₃ ) ₃ SI-OR-SI (CH ₃ ) _{3 is used} , where R is an alkyl radical containing 6 carbon atoms and having normal or isostroyenia. This reagent is obtained by the interaction of alkyltrichlor and dialkylchlorosilanes with alcohols. The reagent has a high hydrophobic activity and good foaming properties, which ensures its high flotation properties. The use of this reagent in the extraction of coal in the froth product makes it possible to increase the extraction of the combustible mass in the concentrate from 86.7 - 92.1 to 90.9 - 94.8% while reducing the consumption of reagent from 1.05 - 1.31 to 0 34 - 0.51 kg / ton. This improves the selectivity of the coal flotation process.

Description

The invention relates to the field of mineral processing by flotation and can be used in coal preparation plants.

The purpose of the invention is to increase the recovery of the combustible mass in the concentrate, to increase the selectivity of the coal flotation process.

The method of coal flotation involves pulping, conditioning the pulp with a reagent, as which bis (trmethylsiloxy) hexane of the general formula (SI) 3Si-0-R-0-Si (CH3) 3 is introduced, where k is an alkyl radical containing b carbon atoms with iso or normal structure, and the release of coal into a frothy product. Bis (trimethylsiloxy) hexane is obtained by reacting alkyl trichloro and dialkyldichlorosilanes with alcohols.

Analogs of bis (trimethylsiloxy) hexane are used as intermediate compounds in organic synthesis, and also as a strong protection of hydroxyl groups in organic synthesis.

The flotation method is carried out as follows.

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The original coal is pulped, conditioned with a complex reagent, followed by coal flotation.

Example: To carry out the process, we take a sample of coal, for example, 100 g, mix it with water in a laboratory machine of the Mechanobr type with a chamber volume of 0.75 liters for 120 seconds, then serve a portion of the complex reagent bis (trimethylsiloxy) hexane and contact it with coal pulp for 60 s. After 60 seconds of contacting the reagents with the pulp, air is supplied to the flotation machine, and then the flotation core is removed for 60 seconds.

The air supply to the pulp is stopped and the next portion of the complex reagent is supplied, followed by their contacting with coal for 60 s.

After contact of the coal sample with reagents, air is again fed into the pulp and the second concentrate is removed, the total consumption of reagents and the number of dosing into the pulp is determined by their flotation activity. The results of the coal fine flotation establish the following. The use of 1,6-bis (trimethylsiloxy) hexane as a complex reagent instead of tractor kerosene with T-6b (95: 5) makes it possible to increase the extraction of the combustible mass in the concentrate from 86.7 ... 92.1% to 90.9. ..94.8% while reducing reagent consumption from 1.05 ... 1.31 kg / t to 0.34 ... 0.51 kg / t. The use of 2,5-bis (trimethylsiloxy) hexane as a complex reagent results in the extraction of the combustible mass in the concentrate within the same limits (90.3 ... 94.7%), but with a reduced consumption of reagent (O, 26 .. O, 40 kg / ton). At the same time, the use of new reagents improves the selectivity of the coal flotation process. In the case of the use of bis (trimethylsiloxy) hexane as reagents, the ash content of the flotation concentrate is reduced by 0.3 ... O, 5% compared with the use of T-66 (95: 5) tractor kerosene as reagents. Comparative tests of organosilicon esters with various lengths of hydrocarbon radicals have shown that the use of 0-bis (trimethylsiloxy) hexanes as an independent

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The solid reagent instead of the ones with the shorter length of the aliphatic radical makes it possible to hang the concentrate yield by 3.0 ... 7.4%, and the ash content of the waste by 9.2 ... 11.9%.

The replacement of the aryl radical with an alkyl one also has a positive effect on the indicators of the flotation process.

Using bis (trimethylsiloxy) hexanes as an independent reagent instead of 0-bis (trimethylsiloxy) benzene allows to increase the yield of flotation concentrate from 75.1 ... 79.0% to 79.8 ... 84.1%. The ash content of waste increases from 48.3 ... 54.1% to 60.4 ... 72.4%. This is due to the fact that, despite spontaneous surface activity (the height of a two-phase foam is 1.5–3.0 times higher than bis- (trimethylsiloxy) hexanes, 0-bis (trimethylsiloxy) beisol is 1.5- The hydrophobization capacity is 2.0 times lower. This has a negative effect on the flotation activity of 0-bis (trimethylsiloxy) benzene if it is used as an independent reagent.

The improvement in coal flotation using bis (trimethylsilyoxy) hexanes is explained by the elemental composition and structure of their molecules.

In bis (trimethylsiloxy) hexanes molecules, electron density is localized on oxygen atoms, as a result, reagents can specifically interact with sorption-active centers of the coal surface that carry a positive charge (protonized hydrogen atoms of the phenolic, carboxyl groups in the macromolecule of the organic mass of coal) according to the scheme

(CHjhSi-o-R-o-51 (sn3) s, vHtB

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where R is an alkyl radical (CH4) 6.

In the bis (trimethylsiloxy) hexanes molecules, there are hydrocarbon radicals that can interact with apolar centers of the coal surface due to intermolecular Van der Waals forces.

Therefore, in the case of adsorption on the coal surface of bis (trimethylsiloxy) hexanes, simultaneous

but both specific (H-bond, etc., and universal non-specific intermolecular forces interacting with positive and apolar portions of the coal surface. This determines their high magnitude and adsorption energy on the coal surface. In this case, the organosilicon compounds are very good hydrophobicizers of the mineral surface when they are adsorbed, which has a positive effect on their flotation activity. It should be noted that the presence of two oxygen atoms in the bis (trimethylsiloxy) hexanes molecule gives and m high surface activity. High polarization of the molecules of the reopnt, caused by the electron-acceptor properties of oxygen atoms, causes good foaming properties.

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The high hydrophobic activity and good foaming properties of bis (trnmethylsiloxy) hexanes ensure their high flotation properties.

Claims (1)

Claims The method of coal flotation, including pulping, conditioning with a silicon-containing reagent and separating coal into a foam product, characterized in that bis (trimethylsiloxy) hexane of the general formula is introduced as silicon-containing reagent to increase the extraction of the combustible mass. (CH3) 3Si-0-R-0-Si (CH,) 5, where K is an alkyl radical containing 6 carbon atoms and having a normal or isotope. 15 20 Editor 0.Speedyh Compiled by L. Antonova Tehred M.DidykKorrektor S.Mekmar Order 40 Circulation 4b5 VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5 Production and publishing plant Patent, Uzhgorod, st. Gagarin, 101. Subscription