SU1364364A1 - Method of coal flotation - Google Patents

Abstract

This invention relates to the beneficiation of minerals. The purpose of the invention is to increase the concentrate yield and reduce reagent costs. The feedstock is conditioned with a collector and blowing agent, using the fraction of recycled caprylic alcohols of dicaprilphthalate production as the collecting foam. The reagent is a waste resulting from side reactions in the synthesis of dicaprilphthalate by esterification of aliphatic alcohols with phthalic anhydride in the presence of a catalyst. The reagent contains high molecular weight hetero polar compounds. Molecules of the latter include hydroxyl OH -, essential C – O – C and ester –C – O – C– groups, aromatic structures and hydrocarbon chains with at least 8 carbon atoms. Use of this reagent in coal flotation instead of dialkyl phthalates with a length of aliphatic radical C , allows to increase the yield of the concentrate from 82.38 to 88.06%, the ash content of the waste from 59.77 to 81.61% while reducing the consumption of reagents by 1.78 times. about b

Description

CO Cf

This invention relates to the enrichment of minerals and can be used in coal flotation.

The aim of the invention is to increase the concentrate yield and reduce reagent costs.

According to the method of coal flotation, including preconditioning of the feedstock with a collector and blowing agent, in the conditioning as a collector 0 2 R - O N

The synthesis of dicapryphthalate is carried out in the presence of an excess of caprylic alcohol (2-ethylhexanol, octanol)

Oh and benzenesulfonic -S-OH in

6

as a catalyst. In the course of the reaction, a so-called raw ether is formed, which contains the so-called COOR, products

adverse reactions: monoether (

: soo

ethers R-0-R, polycondensation products, as well as high molecular weight alcohols, water, catalyst. The mixture of substances formed in the reaction zone is distilled off an excess of alcohol Cg together with the reaction water, and the remaining product is neutralized with lime, washed, dried and separated into the main product, dicaprilphthalate, the catalyst and the fraction of recycled caprylic alcohols, which is a waste of dicaprilphthalate production,

The fraction of circulating caprylic spit production of dicapryphthalate is a clear dark yellow liquid with a faint odor composition, wt.%:

Phthalic diesters

acids

(COOR) 2-6

Caprylic alcohols

R - OH2-4

Mono esters

phthalic acid

. COOR

GN 6 COOMe

4-6

0

the foaming agent introduced a fraction of recycled caprylic alcohols of dicaprilphthalate production,

g The fraction of recycled caprylic alcohols of dicaprilphthalate production is a waste resulting from side reactions in the synthesis of dicaprilphthalate by esterification

0 aliphatic alcohols phthalic anhydride in the presence of a catalyst according to the scheme

COOR

-haHgO

Sooy.

Wild boar

esters R-0-R5-10

Higher unsaturated alcohols and polycondensation products Else

where Me is the metal Ca, Na or K;

R - CH (CH2) 7 1.

25, .

CH - (CH,), -CH-CHj -.

The reagent contains, with its composition iQ, high molecular weight heteropolar compounds, the molecules of which include OH-hydroxyl, C-O-C ester and -C-0-C-ester groups, aromatic structures and hydrocarbon chains with at least eight carbon atoms. The fixation of alcohol molecules on coal particles is carried out mainly due to hydrogen bonds arising between OH groups of alcohols and oxygen-containing portions of the coal surface.

it-.

in ether molecules, there is a local concentration of electron density on the oxygen atom of the ether group, as a result of which the ether group can be fixed specifically on the adsorption centers of the coal surface, bearing a partial positive charge:

Mr. S

  {j N -. - In the carbonyl group,

WITH

part of the ester group of the reagent, the electron cloud

35

50

55

biased to oxygen atom

Due to this displacement, a certain negative charge, S, occurs at the oxygen atom, and a positive positive charge, + S, at the carbon atom. In general, the ester group from the electron point of view has a complex structure, each oxygen entering it (and carbonyl and alkoxy-O-R) is capable of specific interaction with the positive adsorption centers of the coal surface. The energy combination of the aromatic structures, which determines their sorption properties, is due to the nature of the electronic displacements, caused by electron withdrawing substituents in the ortho positions of the benzene ring, exhibiting the induction effect of type-I. As a result of this effect, molecules of mono- and di-substituted esters of phthalic acid are a conjugated system with a concentrated electron density on the ester and carboxyl functional groups and positive charges on the carbon ortho-atoms of the benzene ring. Such an energy state of reagent molecules with a large length of hydrocarbon radicals fixed on apolar centers of the coal surface due to Van der Waals dispersion sequences creates the possibility of simultaneously specific and universal nonspecific interaction with positive and negative centers of the coal surface. Such compounds have not only high hydrophobic ability, but also significant surface activity.

I

 Thus, due to the presence

locally concentrated electron density on oxygen atoms in the carboxyl, ester, ester groups, the presence of TG - bonds, OH - groups, CH and CH, - groups, as well as the long length of hydrocarbon radicals creates the possibility for both specific and nonspecific interaction of reagent molecules as with the surface of the coal, and between themselves, which leads to a high strength of their attachment to the coal particles, polymeric molecules of the ry adsorption and provides a high degree of hydrophobization of the coal surface and, after ovatelno, the collective action of the reagent.

High polarization of the reagent molecules caused by the electron-withdrawing properties of oxygen-containing

About 5

groups, especially -C-0-R, -OH, -C-OMe

ABOUT

with a large length of hydrocarbon radicals, causes a significant surface activity and, therefore, the foaming properties of the proposed reagent, which are necessary for flotation, are fractions of circulating caprylic alcohols produced by dicap rilphthalate.

Example. To carry out the flotation, we take a sample of coal, for example, 0.1 kg, mix it with water in a laboratory machine with a 0.5 liter chamber capacity for 3 minutes. Then a collector-blowing agent is fed - a fraction of circulating caprylic alcohols produced in dicaprilphthalate. After contacting the carbon with the reagent

TO

Air is supplied to the flotation machine for 5 minutes and flotation is carried out. The best indicators are obtained by the proposed method when used as a collector-foaming agent 0 of the fraction of recycled caprylic alcohols produced, dicaprilftylat. Optimum consumption of reagents during flotation of coal, kg / kg 10:

Kerosene1479

5 Dialkyl phthalates 264 Fraction of circulating caprylic alcohols of dicaprilphthalate production Thus, the use of fraction 0 of recycled caprylic alcohols of dicaprilphthalate production during coal flotation instead of dialkyl phthalate with aliphatic radical C ,. allows you to increase the concentrate yield from 5 82.38 to 88.06%, the ash content of the waste from 59.77 to 81.61% while reducing the consumption of the proposed reagent by 1.78 times compared with the known.

The use of a fraction of circulating caprylic 0 spirits of dicaprilphthalate production during coal flotation instead of kerosene and dialkyl phthalates reduces the cost of reagents by 8.72 times, 5

Claims (1)

Invention Formula The method of coal flotation, including pre-conditioning 513643646 the original collector and feeder were introduced into the fraction of recycled nivatep, characterized by caprylic alcohols produced by the di- in the presence of a catalyst.