CN1799716A

CN1799716A - Harmless treatment process for waste chromium slag

Info

Publication number: CN1799716A
Application number: CN 200610010604
Authority: CN
Inventors: 赵建国
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-01-05
Filing date: 2006-01-05
Publication date: 2006-07-12
Anticipated expiration: 2026-01-05
Also published as: CN100413607C

Abstract

The invention relates to an innocent treatment method of waste chromic slag, which comprises: mixing the waste chromic slag, coal ash, zinc stove slag, and red mud at the weight percents of waste chromic slag in 40-45%, the coal ash in 10-15%, the zinc stove slag in 10-15% and the red mud in 28-30% to be broken into 50-80 items and deoxidized sintered in the sintering furnace at the temperature of 1000-1100Deg. C; the sintered mixture after cooled for 2-3 hours is dipped for 20-26 hours to filter the slag via filter cloth, while the filter solution uses FeSO4 as reducing agent whose amount is 14-16 times of Cr6+ of waste chromic slag, therefore, the filter solution can process reducing reaction at the pH valve of 8-8.5; the waste gas generated in sintering is fed into washing tower to be washed, and the generated water vapor is all discharged. The invention can overcome the defect of present method which can not process innocent treatment, to reduce the nocuous elements of waste chromic slag and avoid the environment pollution.

Description

Harmless treatment process for waste chromium slag

Technical field: the innoxious process for treating field that the invention belongs to useless chromium slag.

Background technology: the chromium slag is the waste residue of discharging during sodium dichromate, crome metal are produced, and contains the oxide of magnesium, calcium, silicon, iron, aluminium in the chromium slag and the chrome green that does not react, and also contains water-soluble chromic acid sodium and solubility in acid calcium chromate.Useless chromium slag mainly is that be deposited in as trade waste need not on some vacant lands at present, product that has and technology also will be given up the chromium slag as the raw material of industry, as be used to make calcium magnesium phosphate, cast stone, cement additire or glass and make toner etc., but these all are based on not useless chromium slag were carried out utilizing under the situation of harmless treatment.

Harmful components in the useless chromium slag mainly are sexavalence ions such as water-soluble chromic acid sodium, solubility in acid calcium chromate; In the open the useless chromium slag of Dui Fanging after dash being drenched by rainwater for a long time a large amount of hexavalent chromium with the molten infiltration of the rainwater face of land, to underground water, rivers, the lake produces pollutes, also endanger farmland and aquatic organism, hexavalent chromium is very big to the murder by poisoning of health of human body, its compound has very strong oxidisability, alimentary canal to human body, respiratory tract, skin, mucous membrane and internal organ all have harm, the people of long-term contact hexavalent chromium compound can cause chromium poisoning, and cause headache tired, become thin, apocleisis, the liver kidney also can suffer damage, chromium compound also has carcinogenesis, especially lung cancer; And be utilized as some raw materials of industry without the useless chromium slag of harmless treatment, because the existence of its chemical characteristic can cause secondary pollution to environment.

Summary of the invention: what purpose of the present invention provided in order to overcome the use defective that above-mentioned existing useless chromium slag exists just that a kind of useless chromium is innoxious, resource, technological process do not have that " three wastes " produce is the useless chromium slag innocent treatment method that remarkable environmental-protection function is arranged.

The objective of the invention is to realize by following technological process.

It has following technological process: will give up chromium slag and flyash, zinc kiln slag, red mud are by useless chromium slag 40～45%, flyash 10～15%, zinc kiln slag 10～15%, red mud 28～30% (all is weight percentage, the proportioning total amount is 100%) be crushed to 50～80 orders after evenly mixing and send in the sintering furnace materialization again and handle through 1000～1100 ℃ of high temperature reduction sintering, compound behind sintering water after cooling off 2～3 hours soaks and with filter cloth slag charge was leached in 20～26 hours again, and filtrate is used FeSO ₄As reducing agent, FeSO ₄Addition be Cr in the useless chromium slag ⁶⁺14～16 times of content add FeSO ₄It is to make filtrate through reduction Cr under 8～8.5 the condition at pH value that filtrate is transferred in the back ⁶⁺The back produces sediment and supernatant; The waste gas that compound produces in sintering process is delivered to scrubbing tower, makes the soot particle precipitation after the washing, and the water vapour that washing produces is drained; The present invention also reduces filtrate Cr ⁶⁺The supernatant that the back produces returns in blowback materialization treatment process or the scrubbing tower.

The primary harmfulness of useless chromium slag is its strong basicity, the present invention mixes trade waste flyash, zinc kiln slag, the red mud of acidity through the reduction sintering and carries out materialization processing and neutralization reaction with useless chromium slag, make the calcium ions and magnesium ions in the useless chromium slag be neutralized into harmless salts substances---slag, slag is the immersion by water again, soluble calcium ions and magnesium ions is comprised contain Cr ⁶⁺One of solable matter dissolve into filtrate, produce calcium magnesium phosphate, cast stone, cement additire and be used for sintering deposit ironmaking etc. with regard to making slag after leaching become the neutral raw material of industry, can be used as like this; Useless chromium slag is handled through the materialization of reduction sintering, also makes most hexavalent chromium be reduced into stable chromic salt---slag, and its harmfulness is excluded; The a small amount of hexavalent chromium that contains in slag enters filtrate by the immersion treatment of water, and the hexavalent chromium in the filter residue is eliminated substantially.And the hexavalent chromium in the filtrate is again by adding FeSO in filtrate ₄Make reducing agent, the sediment of the chromic salt of its generation is separated, become a kind of harmless valuable raw material of industry; Remove the supernatant behind the chromic salts, also can be by return the blowback materialization processing stage or the waste gas washing stage recycle, reducing production costs, and make whole process flow accomplish real " the no three wastes ".

At the waste gas that useless chromium slag is carried out producing in the materialization processing procedure mainly is CO ₂, the present invention introduces waste gas and carries out spray washing in the scrubbing tower, makes CO ₂Generate precipitation of calcium carbonate with the supernatant reverse circulation washing of meta-alkalescence, thereby with CO ₂Gas is removed, and the sediment that generates can be used as the production auxiliary materials of common brick and is used; The water vapour that the washing back produces is by the blower fan suction evacuation.

Useless chromium slag after the inventive method is handled, its Cr VI evil and other harmfulnesses are excluded, but safety and environmental protection enter the raw material of industry and utilize the field, and the supernatant that produces in the innoxious process returns and recycles, and has not only reduced cost but also do not have discharging of waste liquid; The inventive method cost is low, and the disposal amount is big, and is very wide to the comprehensive utilization prospect of useless chromium slag.

Further set forth content of the present invention below in conjunction with drawings and Examples.

Description of drawings: Fig. 1 is the inventive method process chart;

Fig. 2 is for returning supernatant the process chart that recycles on Fig. 1 basis.

The specific embodiment:

Embodiment one: as Fig. 1, with useless chromium slag of 430kg and 150kg flyash, the 120kg zinc kiln slag, it is thin to be crushed to 80 orders with ball mill after the 300kg red mud evenly mixes, send into the sintering furnace materialization and handle, adopt 1050 ℃ of high temperature sinterings to come out of the stove after 3 hours and cooled off 2 hours, clinker is crushed to the thin water of 50 orders it was soaked 24 hours, with filter cloth slag charge is leached, filtrate is used FeSO again ₄As reducing agent, FeSO ₄Adding carry out reduction reaction for 15 times of the hexavalent chromium measured in the filtrate in a large number, add FeSO ₄The back transfers filtrate to make hexavalent chromium in the filtrate be reduced into the harmless sediment of chromic salt under pH value is 8 condition; The waste gas that produces in sintering process is sucked sends into spray washing in the scrubbing tower, and the sediment that the washing back generates is removed, and the water vapour that washing produces is by the blower fan suction evacuation.

Embodiment two: see figure two, with useless chromium slag of 450kg and 100kg flyash, the 150kg zinc kiln slag, it is thin to be crushed to 50 orders with ball mill after the 300kg red mud evenly mixes, send into the sintering furnace materialization and handle, adopt 1000 ℃ of high temperature sinterings to come out of the stove after 4 hours and cooled off 3 hours, clinker is crushed to the thin water of 50 orders it was soaked 22 hours, with filter cloth slag charge is leached, filtrate is used FeSO again ₄As reducing agent, FeSO ₄Adding in a large number carry out reduction reaction for 14 times of the hexavalent chromium measured in the useless chromium slag, add FeSO ₄The back transfers filtrate to make hexavalent chromium in the filtrate be reduced into the harmless sediment of chromic salt under pH value is 8.2 condition; The waste gas that produces in sintering process is sucked sends into spray washing in the scrubbing tower, and the sediment that the washing back generates is removed, and the water vapour that washing produces is by the blower fan suction evacuation.Filtrate being reduced removed Cr ⁶⁺After supernatant be collected the processing stage of returning the blowback materialization by pipeline or the waste gas washing stage recycles.

Embodiment three: see figure two, with useless chromium slag of 400kg and 150kg flyash, the 150kg zinc kiln slag, it is thin to be crushed to 60 orders with ball mill after the 300kg red mud evenly mixes, sending into the sintering furnace materialization handles to the cooling 3 hours of coming out of the stove after 4 hours of 1100 ℃ of high temperature sinterings, clinker is crushed to the thin water of 50 orders it was soaked 20 hours, with filter cloth slag charge is leached again, and filtrate is used FeSO ₄As reducing agent, FeSO ₄Adding in a large number carry out reduction reaction for 16 times of the hexavalent chromium measured in the useless chromium slag, add FeSO ₄The back transfers filtrate to make hexavalent chromium in the filtrate be reduced into the harmless sediment of chromic salt under pH value is 8.5 condition; The waste gas that produces in sintering process is sucked sends into spray washing in the scrubbing tower, and the sediment that the washing back generates is removed, and the water vapour that washing produces is by the blower fan suction evacuation.Filtrate being reduced removed Cr ⁶⁺After supernatant be collected the processing stage of returning the blowback materialization by pipeline or the waste gas washing stage recycles.

Claims

1, harmless treatment process for waste chromium slag, it is characterized in that, it has following technological process: will give up chromium slag and flyash, zinc kiln slag, red mud are by useless chromium slag 40～45%, flyash 10～15%, zinc kiln slag 10～15%, red mud 28～30% (all is weight percentage, the proportioning total amount is 100%) be crushed to 50～80 orders after evenly mixing and send in the sintering furnace materialization again and handle through 1000～1100 ℃ of high temperature reduction sintering, compound behind sintering water after cooling off 2～3 hours soaks and with filter cloth slag charge was leached in 20～26 hours again, and filtrate is used FeSO ₄As reducing agent, FeSO ₄Addition be Cr in the useless chromium slag ⁶⁺14～16 times of content add FeSO ₄It is to make filtrate through reduction Cr under 8～8.5 the condition at pH value that filtrate is transferred in the back ⁶⁺The back produces sediment and supernatant; The waste gas that compound produces in sintering process is delivered to the scrubbing tower washing, makes the soot particle precipitation after the washing, and the water vapour that washing produces is drained.

2, harmless treatment process for waste chromium slag according to claim 1 is characterized in that filtrate is reduced Cr ⁶⁺The supernatant that the back produces returns in blowback materialization treatment process or the scrubbing tower.