CN1181996A

CN1181996A - Deep physical coal deliming and desulphurizing technology

Info

Publication number: CN1181996A
Application number: CN 97116584
Authority: CN
Inventors: 王祖讷; 朱书全; 杨巧文; 姜季云; 傅晓恒; 孙宗岳; 张文富; 许泽胜; 任守政; 王新国; 王受路
Original assignee: Beijing Graduate School Of China University Of Mining And Technology
Current assignee: Beijing Graduate School Of China University Of Mining And Technology
Priority date: 1997-09-17
Filing date: 1997-09-17
Publication date: 1998-05-20
Anticipated expiration: 2017-09-17
Also published as: CN1098127C

Abstract

First, coal is crushed to fully disaggregate combustible organic matter from inorganic mineral in superfine stirring mill; then the low-ash and low-sulphur refined coal grains after disaggregation are flocculated into flocs under the shearing and stirring effect of emulsified nonpolar oil in floc generator; and finally, the flocs are floated through foam floatation and the floated flocs are filtered in filter press, formed and dried thermally to produce low-ash and low-sulphur refined coal product.

Description

Deep physical coal deliming and desulphurizing technology

The present invention relates to a kind of coal physical method degree of depth deliming and desulphurizing coal preparation technique.

Because the disseminated grain size of inorganic mineral is very thin in the coal, Zhong Guo coking coal particularly, be difficult to therefrom to select ash content with the coal preparation method of routine and be lower than 6% low ash extract coal, even some coal can be selected this low ash extract coal with the high sink float of sharpness of separation, but its clean coal yield descends significantly, and is uneconomical.Be lower than 1% ultra clean coal and can't realize especially and will select ash content with physical method.In addition, the pyritous disseminated grain size in many kind coals also is very thin, and this pyrite is difficult to effectively remove with conventional coal preparation method equally.

For indivedual coals, after the ultra-fine grinding of raw coal process, can select ash content with the method for oil aggregation and be lower than 1% ultra clean coal, but because the oil consumption height can't be put to industrial production.The U.S. once used the bridging agent of pentane as the oil aggregation method, though can reduce the medicine consumption by reclaiming bridging agent, because the danger of potential blast, whole system must seal, and protects with inert gas, sorting cost height, and its pilot scale line is removed.

Can produce ash content with chemical method and be lower than 1% ultra clean coal, but because of the need strong acid and strong base, cost height and contaminated environment also can't be applied to industrial production.

Describe the implementation of degree of depth deliming and desulphurizing task of the present invention in detail below in conjunction with accompanying drawing.For granularity greater than the feed coal of 2mm (as the gravity treatment cleaned coal, in the gravity treatment coal etc.), earlier through in small, broken bits to less than feeding ultra-fine grinding mill behind the 2mm.If the granularity of feed coal can directly feed ultra-fine grinding mill less than 2mm (as floatation clean coal, floating tail-coal and sedimentation basin coal slime etc.).Organic flammable body and inorganic mineral that feed coal is milled in ultra-fine grinding mill wherein fully dissociate, again the product water behind the mill is made into the coal slurry that weight concentration is 5-10%, press the non-polar oil of the amount adding of feed coal 0.5-10 kilogram per ton through emulsification, if will select the cleaned coal of low sulphur content, then to add the pyrite inhibitor, in order further to reduce cleans ash, add dispersant to alleviate of the covering of high plaster pledge to coal grain surface.Again coal slurry is fed the floc sedimentation generator of high shear rate.Under the non-polar oil and high shear stirring action of emulsification, the purer coal particle through dissociateing relies on its natural hydrophobicity, overcomes the electrostatic repulsion between the coal grain and forms floc sedimentation, utilizes conventional froth flotation that floc sedimentation is sorted out from the grey tail coal of height then.Several selected links are set, to satisfy the requirement of different final cleans ash.The cleaned coal of selecting with the filter press dehydration, in order further to reduce the moisture of cleaned coal, has increased the shaping and drying link again.

The technology of this invention is different from present froth flotation, oil aggregation choosing or selective flocculation sorting process on separating mechanism.Though the dosage of conventional froth flotation is approaching with this technology, its can't sorting through the feed coal behind the ultra-fine mill.The oil aggregation choosing is that the cleaned coal particle of low ash forms closely knit little under the parcel of non-polar oil, and little granule is to use screen filtration with separating of the grey tail coal of height.Though this method can the fine beans of sorting, its dosage can't be accepted economically up to feed coal 20-50 kilogram per ton.The flocculant that selective flocculation adopts is a macromolecule organic, big and loose many of the floc sedimentation that the floc sedimentation of its formation forms than technology of the present invention, so its mechanical entrapment to the grey tail coal of height is serious, sharpness of separation is low.

Characteristics of the present invention are:

1. adopted low energy consumption to stir the ultra-fine feed coal that grinds of mill, inorganic mineral and the organic flammable body that embedding cloth is very thin in the feed coal fully dissociated.Created condition for selecting low grey low-sulfur cleaned coal;

2. utilize the natural hydrophobicity of coal to add the invigoration effect of non-polar oil, under the high shear stirring action, make the microfine cleaned coal particle of low grey low-sulfur form floc sedimentation.Because of floc sedimentation is thinner, reduce the consumption of non-polar oil greatly, add emulsifying technology to non-polar oil, make the consumption of non-polar oil only be feed coal 0.5-10 kilogram per ton.Because the floc sedimentation size is less, obviously alleviated the mechanical entrapment of floc sedimentation simultaneously, improved sharpness of separation the grey tail coal of height;

3. in order further to reduce the mechanical entrapment of cleaned coal floc sedimentation to the grey tail coal of height, improve sharpness of separation, can adopt two-way floc sedimentation method, promptly use non-polar oil floc sedimentation microfine cleaned coal particle, with electrolyte or high molecular polymer flocculation or the high grey tail coal particle of floc sedimentation microfine;

4. made full use of the high characteristics of froth flotation sharpness of separation, the cleaned coal floc sedimentation has been sorted out from the grey tail coal of height, and be provided with several selected links according to requirement difference to final cleans ash;

5. utilize the cleaned coal floc sedimentation dehydration of filter press,, can improve its dehydrating effect, add, the moisture of head coal product is further reduced filter cake moulding heating power drying because cleaned coal is the floc sedimentation shape to sub-electing.

It is as shown in the table to the separation results of several feed coals of difference for technology of the present invention, by this separation results as seen, when the raw material pit ash is low, can obtain the ultra clean coal of high yield, shown in 4,6 and No. 7 tests.And for coal slime and floating tail-coal outside the higher middle coal of ash content, the factory, all optionally go out ash content and be lower than 12% cleaned coal, and clean coal yield is all more than 50%, that is to say, for these cheap products of coal preparation plant, use this technology, from 2 tons, can select at least in coal or the tail coal to meet more than 1 ton and sell the head coal product that requires.By No. 2 tests as seen, this sorting process desulfurized effect is fairly obvious, and its sulphur content drops to 0.51% of cleaned coal by 2.99% of feed coal, and desulfurization degree reaches 88.19%.

Table physical depth deliming and desulphurizing technology is to the separation results of different coals

Test number	Coal	Feed coal		Cleaned coal		The flammable body rate of recovery, %	Desulfurization degree %
		Feed coal		Cleaned coal				A _ad，％	S _t，ad，％	A _ad，％	??γ，％	S _tad，％
		??1	Coal in the coking coal	??32.1	??11.2			A _ad，％	S _t，ad，％	A _ad，％	??γ，％	S _tad，％	??69.8	??91.3
??2	Coal in the high-sulfur coking coal	??1	Coal in the coking coal	??32.1	??11.2	??28.88	?2.99	??8.96	?69.21	?0.51	??87.61	?88.19	??69.8	??91.3
??2	Coal in the high-sulfur coking coal	??3	Coal slime outside the coking coal factory	??39.7	??11.6	??28.88	?2.99	??8.96	?69.21	?0.51	??87.61	?88.19	??72.2	??90.8
??4	Coal slime outside the smokeless coal works	??3	Coal slime outside the coking coal factory	??39.7	??11.6	??17.1		??1.6 ??3.1	??51.8 ??74.0		??61.5 ??86.5		??72.2	??90.8
??4	Coal slime outside the smokeless coal works	??5	1/3 coking coal floating tail-coal	??29.72	??8.29 ??8.83 ??8.87	??17.1		??1.6 ??3.1	??51.8 ??74.0		??61.5 ??86.5		??60.24 ??63.48 ??68.05	??78.61 ??82.83 ??88.40
??6	Long flame coal cinder cleaned coal	??5	1/3 coking coal floating tail-coal	??29.72	??8.29 ??8.83 ??8.87	??3.11		??1.36 ??1.42 ??1.50	??73.5 ??82.3 ??89.1		??74.8 ??83.7 ??90.6		??60.24 ??63.48 ??68.05	??78.61 ??82.83 ??88.40
??6	Long flame coal cinder cleaned coal	??7	The anthracite floatation clean coal	??7.89	??0.54 ??0.74 ??1.17	??3.11		??1.36 ??1.42 ??1.50	??73.5 ??82.3 ??89.1		??74.8 ??83.7 ??90.6		??44.75 ??53.59 ??65.74	??48.92 ??57.75 ??70.54

The present invention can be applied to:

1. reduce the ash content of coking coal cleans significantly, be lower than 6% for production high-quality metallurgical coke and cupola coke provide ash content, sulphur content is lower than 1% quality fine coal product.For the design that realizes this purpose is, at first selects ash content in advance and be lower than 6% low ash extract coal, as the part of final low ash extract coal product with conventional gravity preparation.Get rid of high grey spoil and oarse-grained pyrite in the raw coal simultaneously, its middle material sub-elects ash content with this technology again and is lower than 6% low ash extract coal, merges as final low ash extract coal product with low grey piece cleaned coal again;

2. the ash content that obtains high yield from common washing cleaned coal or low grey raw coal is the ultra clean coal of 1.5-2.0%, goes out ash content and is lower than 1.0% ultrapure coal indivedual coals are also optional.These ultralow culms are preparation top-grade active carbons, substitute the petroleum coke manufacturing electrode of import, manufacturing as the substitute of the carbon black of filler and the quality raw materials of other carbon industry demand.Also can prepare the Coal Slurry that replaces heavy diesel fuel with this ultralow culm;

3. handle coal in coal slime, floating tail-coal and the gravity treatment of rare coal (as the coking coal and the rich coal of China) coal preparation plant.These colm sales difficulties are stacked or all serious environment pollutions that acts as a fuel.Utilize this technology, can therefrom select to meet and sell the cleaned coal that requires, promptly solved it and stacked problem of environment pollution caused, created economic benefit again, saved rare coal resources;

4. when utilizing this technology to select low ash extract coal, its fine intermediate product directly is prepared into water-coal-slurry as boiler oil.And its ash content itself is exactly a kind of good raw material of developing building materials up to 70% the grey tail coal of ultra-fine height.

Claims

One kind making after the feed coal ultra-fine grinding organic flammable body and inorganic mineral fully dissociate in the coal, by floatingly selecting the deep physical deliming and desulphurizing coal preparation technique of low-dust low-sulfur coal behind the selectivity floc sedimentation.Technical characterictic of the present invention is:

A. feed coal ultra-fine grinding organic flammable body and inorganic mineral to the feed coal are fully dissociated;

B. in the raw material coal slurry of ultra-fine grinding, add non-polar oil, make the microfine in the coal slurry low grey with the high shear rate mode again through Over emulsfication

Particle shape becomes floc sedimentation;

C. with froth flotation floc sedimentation is sorted out from coal slurry;

D. the low ash extract coal floc sedimentation that sub-elects dewaters with filter press, and filter cake is after moulding, and the heating power drying further reduces moisture again;

E. the ash content of selecting with this technology is lower than 6% the low ash extract coal raw material as metallurgical coke or cupola coke;

F. the ash content of selecting with this technology is 1.5-2% or is lower than 1.0% ultralow grey cleaned coal as making active carbon, substituting the petroleum coke system of import

Mfg. electrode, make carbon black as filler, as the raw material of other carbon material or be prepared into the Coal Slurry that substitutes heavy diesel fuel;

G. use this technology from colm (as coal, floating tail-coal or coal slime the gravity treatment), to select ash content and meet the cleaned coal of selling requirement,
2. according to the described sorting process of claim 1, when it is characterized in that granularity when feed coal is greater than 2 millimeters, comprise link in small, broken bits before the ultra-fine mill;
3. according to the described sorting process of claim 1, it is characterized in that feed coal fully dissociates with wherein organic flammable body and inorganic mineral through the granularity of ultra-fine mill to be as the criterion that the scope of the mean particle size D [4.3] behind its mill is the 4-100 micron;
4. according to the described sorting process of claim 1, it is characterized in that will impose high shear to coal slurry when cleaned coal forms floc sedimentation stirs, and add non-polar oil that the consumption of non-polar oil is 0.5 kilogram-10 kilograms of feed coals per ton through emulsification;
5. according to claim 1 and 4 described sorting process, it is characterized in that the grey tail coal of height being flocculated with electrolyte or high polymer for reducing selected link and improving sharpness of separation, the consumption of electrolyte or high polymer is 0 milligram-500 milligrams of feed coals per ton;
6. according to the described sorting process of claim 1, it is characterized in that in the floc sedimentation forming process, further reducing cleans ash, reduce the sulphur content of cleaned coal with the pyrite inhibitor with dispersant;
7. according to the described sorting process of claim 1, the dosing place that it is characterized in that above-mentioned flocculant, dispersant and inhibitor is in grinding machine or in the floc sedimentation generator;
8. according to the described sorting process of claim 1, it is characterized in that according to requirement difference, the selected link of different number of times being set to final cleans ash with froth flotation sorting cleaned coal floc sedimentation;
9. according to the described sorting process of claim 1, it is characterized in that when the sorting ash content is lower than 6% cleaned coal, select the pure cash that ash content in the raw coal is lower than 6% cleaned coal and gets rid of high ash in advance with the gravity preparation of routine, its middle product sub-elects ash content with this technology and is lower than 6% low ash extract coal, and the low ash extract coal of selecting thus mixes with the low ash extract coal of preliminary election as final cleaned coal again;
10. according to the described sorting process of claim 1, it is characterized in that the ash content of selecting is lower than 6%, sulphur content is lower than 1.0% the cleaned coal raw material as metallurgical coke or cupola coke;
11., it is characterized in that the ash content of selecting is lower than petroleum coke that 1.0% ultralow culm is used to prepare top-grade active carbon, substitute import and makes Coal Slurry that electrode, preparation replace heavy diesel fuel, replaces carbon black or as the raw material of other carbon industry as the high-quality filler according to the described sorting process of claim 1.