CN105648206A - Steelmaking sludge recycling method - Google Patents

Abstract

The invention discloses a steelmaking sludge recycling method, and relates to comprehensive utilization of rotary furnace smelting iron-containing soot, in particular to a method for producing iron blocks for steelmaking through the rotary furnace smelting iron-containing soot. The steelmaking sludge recycling method aims to reduce iron consumption during steelmaking and dissolution consumption. The method comprises the technological procedures that (1) steelmaking sludge is screened, specifically, according to the granularity requirements, the steelmaking sludge of more than 20 meshes accounts for less than or equal to 2.0 % of the total weight, and TFe accounts for 56% of the total weight; (2) grinding is conducted with the time being controlled to be 28 min; (3) screening classification is conducted to control the granularity of the steelmaking sludge to be less than 40 meshes; (4) drying is conducted, the weight in wet base before drying is controlled to be 9 wt%, and the weight in wet base after drying is controlled to be 1 wt%; (5) magnetic separation is carried out, the weight of impurities in the steelmaking sludge is controlled to be 3.6 wt% after magnetic separation; and (6) molding is carried out, specifically, 2 wt% of bentonite as a bonding agent is added and mixed with 98 wt% of the steelmaking sludge evenly, and the mixture is processed into the required iron blocks.

Description

A kind of steel-smelting sewage sludge recycling method

Technical field

The present invention relates to the comprehensive utilization of converter refining iron-containing dust, especially belong to the method for producing steely iron piece with converter refining iron-containing dust.

Background technology

Steel-smelting sewage sludge (hereinafter to be referred as mud) is the byproduct of oxygen top-blown converter dedusting, is a kind of secondary resource of preciousness. Steel-smelting sewage sludge material characteristic: it is large that steel-smelting sewage sludge has chemical component fluctuation, iron-holder is high, and basic anhydride content is high, and fine size. From chemical composition, mud can be used as sintering, pellet feed is used aborning, rationally use mud, not only can replace part iron-bearing material, can also replace part binding agent, flux, simultaneously both reduced production cost, and reduced again the strategy that steel mill's blowdown implements energy-saving and emission-reduction, cost efficiency for Baogang and there is considerable meaning.

Mud is good ferriferous raw material, domestic at present the mode of its utilization is had following several: (1) directly returns to sintering utilization as batching, and its pollution effect causing to environment is very large, easily clumps together separately, be difficult for mixing, affect the enthusiasm that Enterprise Integrated utilizes. (2) adopt and be piped to sintering plant whitewashing utilization, closely steel-smelting sewage sludge can be concentrated to certain solid concentration, pipeline is delivered to that sintering is prepared burden and alternative sintering make-up water. (3) adopt and be squeezed into mud pelletizing, do steelmaking slag agent cooling agent and use, all obtained good effect. Along with the attention of country to environmental protection temperature, management and the law enforcement dynamics of converter mud that country produces iron and steel enterprise strengthened increasingly, moreover because the factor such as energy shortage and rise in price has badly influenced the development of China's steel industry. If better utilize mud, method and the approach of seeking renewal are imperative.

Chinese patent 200910273228.7, denomination of invention is to give up to utilize steel-smelting sewage sludge to produce the method for steely iron piece, the present invention relates to the method for producing steely iron piece with converter refining iron-containing dust, its step: steel-smelting sewage sludge is sieved, and+20 object steel-smelting sewage sludges account for total weight percent≤3%; Carry out grinding; Carry out sieve classification, its granularity is controlled at-40 orders; Be dried, moisture before it is dry is≤10%, dried moisture be≤1%; Carry out magnetic separation, after choosing, its impurity is≤5%; Carry out moulding: the sponge iron of the percentage by weight 95～97.5% containing Tfe is mixed with the steel-smelting sewage sludge after magnetic separation, and its granularity accounts for 8～20% for-100 object sponge iron, and steel-smelting sewage sludge is 92～80%; Or aforementioned after treatment account for the iron block that is processed into needs after 98～95% steel-smelting sewage sludge evenly mixes as bonding agent with 2～5% bentonites. But the deficiency of this invention is complex technical process, technological parameter and iron block quality are difficult to control, Chinese patent 200510012447.1, denomination of invention is the method with shaft roasting sludge ball of steel smelting, this invention has proposed a kind of method with shaft roasting sludge ball of steel smelting, comprise the mud that steel-making produces in dust removal process, by mud per ton, add soap scholar, join in forced stirrer, stir and evenly mix for subsequent use; Pug after mixing is put in roll type ball press and is pressed into sludge ball, the green-ball pressing is put into process shaft roasting in shaft furnace, naturally cool, become the sludge ball of finished product. But because the required financial cost of this technology is higher, be difficult to accomplish to promote the use of on a large scale.

Summary of the invention

In order to solve deficiency and the problem of existing mud recovery technology, provide a kind of method that meets environmental protection resource circulation utilization to iron and steel enterprise. The present invention aims to provide a kind of steel-smelting sewage sludge recycling method, in reducing the consumption of steel-making iron charge, can reduce again and dissolve the method consuming.

The technical solution adopted for the present invention to solve the technical problems is: with addition of 3%～4% steel-smelting sewage sludge, can reduce by 0.

7%～0.9% bentonite, pellet raw material expense can reduce by 7.2～9.6 yuan/t. Ironmaking sludge carbon containing, is the good raw material that is used as SINTERING PRODUCTION, has the advantages that to reduce sintering solid fuel consumption, be beneficial to sintering granulating. If steel-making ironmaking sewage adopts once, secondary sedimentation tank precipitation, thereafter by plate and frame filter press filter-press dehydration, dry again or natural drying, mud can dewater to below 13%, and now mud has laxity, and transport and explained hereafter are with addition of easy realization, but the Treatment of Sludge time is long, manpower and materials have high input, and treatment operating costs is up to 80～100 yuan/t, and one-time investment approximately needs more than 8,000,000 yuan, and can further expand the pollution of environment, mud utilize cost very high. Through research, test and contrast, think adopt mud cream utilize mode most economical rationally. Steelmaking and ironmaking sludge water is by once or after secondary sedimentation tank precipitation, adopt plate and frame filter press or the dehydration of super horizontal type screw settling centrifuge, be easy to be dewatered to moisture 40% left and right, operating cost is low, especially adopts super horizontal type screw settling centrifuge dehydration, and operating cost is approximately only 13 yuan/t, mud transport after treatment does not spill, transport not airborne dust, be beneficial to environment maintenance, all Treatment of Sludge.

Steel-smelting sewage sludge technological process is: concentration 2%～5% produced by wet dust removal of converter sewage; first be precipitated to concentration 30% left and right through first and second sedimentation basin; again by plate and frame filter press press filtration to sludge concentration 60%～65%; adopt dumper to be transported to the special sludge bin of pelletizing plant, mud is allocated in raw material with addition of machine by mud; Ironmaking sludge technological process is: concentration 2% wet dedusting ironmaking sewage, be precipitated to concentration 15%～20% through primary sedimentation basin, use again domestic horizontal screw centrifugal dewaterer by sludge dewatering to concentration 60%～65%, adopt dumper to be transported to the special storehouse of sintering plant mud, mud is allocated in raw materials for sintering with addition of machine by mud.

Compared with prior art beneficial effect of the present invention.

The present invention has adopted brand-new technology, solve the stable not problem of prior art products performance, greatly improve the recovery utilization rate to waste and old refractory material, ensure that mud can keep continuous processing and utilizing simultaneously, substantially occupied ground no longer, mud is no longer transported outward and contaminated environment, has obvious environment protecting.

Detailed description of the invention

Embodiment 1:

1) steel-smelting sewage sludge is sieved to its granularity requirements :+20 object steel-smelting sewage sludges account for total weight percent≤2.0%, and TFe accounts for 56% of total weight percent;

2) carry out grinding, time control is 28 minutes;

3) carry out sieve classification, its granularity is controlled at-40 orders;

4) be dried, it controls dry front wet weight percentage is 9%, and dried wet weight percentage is 1%;

5) carry out magnetic separation, the percentage by weight of controlling its impurity after choosing is 3.6%;

6) carry out moulding: add percentage by weight be 2% bentonite as bonding agent, the steel-smelting sewage sludge that is 98% with percentage by weight is processed into the iron block of needs after evenly mixing.

Embodiment 2:

1) steel-smelting sewage sludge is sieved to its granularity requirements :+20 object steel-smelting sewage sludges account for total weight percent≤1.6%, and TFe accounts for 60% of total weight percent;

2) carry out grinding, time control is 25 minutes;

3) carry out sieve classification, its granularity is controlled at-40 orders;

4) be dried, it controls dry front wet weight percentage is 6%, and dried wet weight percentage is 0.8%;

5) carry out magnetic separation, the percentage by weight of controlling its impurity after choosing is 3.0%;

6) carry out moulding: add percentage by weight be 3.0% bentonite as bonding agent, the steel-smelting sewage sludge that is 97% with percentage by weight is processed into the iron block of needs after evenly mixing.

Embodiment 3:

1) steel-smelting sewage sludge is sieved to its granularity requirements :+20 object steel-smelting sewage sludges account for total weight percent≤1.8%, and TFe accounts for 64% of total weight percent;

2) carry out grinding, time control is 30 minutes;

3) carry out sieve classification, its granularity is controlled at-40 orders;

4) be dried, it controls dry front wet weight percentage is 8.5%, and dried wet weight percentage is 0.7.6%;

5) carry out magnetic separation, the percentage by weight of controlling its impurity after choosing is 1.1%;

6) carry out moulding: add percentage by weight be 5.0% bentonite as bonding agent, with percentage by weight be 95%.

Claims (1)

1. a steel-smelting sewage sludge recycling method, is characterized in that according to following technological process operation:

1) steel-smelting sewage sludge is sieved to its granularity requirements :+20 object steel-smelting sewage sludges account for total weight percent≤2.0%, and TFe accounts for 56% of total weight percent;

2) carry out grinding, time control is 28 minutes;

3) carry out sieve classification, its granularity is controlled at-40 orders;

4) be dried, it controls dry front wet weight percentage is 9%, and dried wet weight percentage is 1%;

5) carry out magnetic separation, the percentage by weight of controlling its impurity after choosing is 3.6%;

6) carry out moulding: add percentage by weight be 2% bentonite as bonding agent, the steel-smelting sewage sludge that is 98% with percentage by weight is processed into the iron block of needs after evenly mixing.