CN104874583A - Comprehensive treatment method of dry reclaimed dust of blast furnace - Google Patents

Abstract

The invention relates to a comprehensive treatment method of dry reclaimed dust of a blast furnace. The reclaimed dust mainly comprise the following ingredients: 15-25% of TFe, 14-30% of C, 4-6% of Zn, 5-7% of alkali metal salt, 0.5-1.9% of cyanide, 8-10% of SiO2, 2-3% of Al2O3, 15-21% of CaO and MnO, and small amounts of combined-state Pb and Cu or simple substances Pb and Cu. The technological process comprises the steps of unloading the dust, mixing, carrying out ball milling, performing flotation, reselecting and carrying out water treatment. After the method is applied to the dry reclaimed dusts of the blast furnace, environment-protection indexes reach the standard, and the contents of alkali metal, lead and zinc entering ore matching for sintering directly can be reduced greatly; the yield of fine powdered iron in dry reclaimed dusts is improved by 5-10%, the yield of the recycled carbon dusts is improved by 8-10% and the equipment failure rate is reduced remarkably.

Description

The integrated conduct method of blast furnace dry type dedusting ash

Technical field

The invention belongs to comprehensive utilization of resources and environmental protection technical field, be specifically related to a kind of integrated conduct method of blast furnace dry type dedusting ash.

Background technology

Steel mill can carry out dry method dust to blast furnace dust, gas mud etc. usually, obtains a kind of dry dust removal ash (being called for short " dry method ash ").For certain steel enterprise, containing the alkalinous metal salinity of 5.0% ~ 7.0% in this blast furnace dry method dust ash, Zn content 4.0 % ~ 6.0%, cyanide content 0.05 % ~ 0.19 %, to alkali metal load and the Zn load of blast furnace be increased as directly returned Iron Ore Matching in Sintering, totally unfavorable to smooth operation of furnace.

Prior art generally adopts the method for cycling water ore dressing to this dedusting ash, and this this goes make recirculated water constantly concentrated and enrichment, salinity, CN in system ^-content rises, and pH value increases, and concerning surrounding environment being a larger hidden danger, and is greatly affected due to the higher ore-sorting system that makes of water quality basicity.Dissolve the salinity in ferrous material and cryanide ion in recirculated water, cause the salinity of system, cryanide ion higher.By the impact of technique, the harmful element content that dry method ash contains is higher, and through circulation, constantly concentrate, in recirculated water, salinity can reach about 12% ~ 13%, and cryanide ion can reach 1800 ~ 2000 ppm.

Along with the pay attention to day by day to environmental protection, it is enterprise's problem demanding prompt solution that the separation of dry method ash active ingredient and environmental protection utilize.

Summary of the invention

The object of the present invention is to provide a kind of integrated conduct method of blast furnace gas dry type bag-type dust ash.

Technical scheme of the present invention: the integrated conduct method of blast furnace dry type dedusting ash, described dedusting ash main component comprises: TFe=15% ~ 25%, C=14% ~ 30%, Zn=4% ~ 6%, alkali metal salt=5% ~ 7%, cyanide=0.5% ~ 1.9%, SiO ₂=8% ~ 10%, Al ₂o ₃=2% ~ 3%, CaO+MgO=15% ~ 21%, all the other are a small amount of Pb, Cu chemical combination state or simple substance.Technological process comprises unloads ash-stirring-ball milling-flotation-gravity treatment-water treatment.Its processing step is:

(1) ash is unloaded: dry method ash unloads ash and puts into material pond and exist side by side and namely use recirculated water immersion treatment.

(2) stir: add water dry method ash the mud dispersed with stirring being configured to 20% ~ 30% concentration.

(3) ball milling: the ore pulp after stirring enters ball mill grinding, makes caking and coarse particulate matter obtain grinding dispersion.

(4) flotation: according to ore pulp after mineral grain fully disperses: floating agent: diesel oil=90 ~ 100: the ratio of 1 ~ 1.2: 0.35 ~ 0.45 stirs, utilize flotation device to be sorted out by carbon wherein, what obtain carbon containing > 75% utilizes carbon.

(5) gravity treatment: select the ore pulp after carbon to adopt spiral chute and shaking table to carry out gravity separation, the Iron concentrate obtained containing full iron 45% ~ 50% is recycled for sintering.

(6) water treatment: regularly add ferrous sulfate according to the amount of 50 ~ 70 times of cyanide ion concentration in water system, total cyanogen is reduced to 15 below ppm.

After Filter Press, filtrate is the waste water of alkali metal containing salt, also may be used for smelting iron washing slag water.After discharge of wastewater, production system replaces salary again.

Progressive effect of the present invention: after dry method ash implements the method, environmental protection index can be up to standard, greatly reduces the content of the alkali metal directly entering into Iron Ore Matching in Sintering, plumbous zinc simultaneously.In dry method ash, Iron concentrate recovery rate improves 5% ~ 10%, and reclaim carbon dust recovery rate and improve 8% ~ 10%, equipment failure rate obviously reduces.Because of a little, the inventive method, by reducing the harm of harmful element, can effectively utilize iron-containing waste, for the normal operation of blast furnace and the integrated treatment of blast furnace dry method ash provide a new method.

Detailed description of the invention

Embodiment 1: the integrated conduct method of blast furnace gas dry type bag-type dust ash

3# blast furnace dedusting ash Main Ingredients and Appearance content is as table 1.

Table 1 3# blast furnace dedusting ash Main Ingredients and Appearance content

Treatment process steps is:

(1) ash is unloaded: 3# blast furnace dry method ash 20t is put into material pond and exist side by side and namely use recirculated water immersion treatment.

(2) stir: use 5t clamshell crane to grab 5 buckets and put into the agitator that diameter is 2.5m, in agitator, add water 2.2 m deeply, being configured to pulp density is 26.2 %, stirs after 15 minutes for subsequent use in agitator.

(3) ball milling: the ore pulp after stirring enters ball mill and carries out ore grinding, makes bulk lump and coarse particulate matter obtains grinding dispersion, is convenient to the ore dressing resolution ratio of follow-up flotation and gravity separation technology.

(4) flotation: ore pulp enters 4A flotation device after ball mill, ore pulp is joined according to real: floating agent: diesel oil=98: the ratio of 1.01: 0.38 adds in agitator simultaneously carries out stirring reaction after mineral grain fully disperses, utilize 4A flotation device to carry out selecting carbon, the carbon content after flotation device flotation is 82.1%.Meet the requirement of iron-making coal-injecting to carbon content.

(5) gravity treatment: select the ore pulp after carbon to utilize the heavy physical property of iron compound to adopt spiral chute and shaking table to carry out gravity separation, the Iron concentrate obtained containing full iron 52.3% is recycled for sintering.

(6) water treatment: circulate after 35 days, cyanide ion concentration 1380 ppm in system, the water yield amounts to 300 tons, after adding ferrous sulfate, total cyanogen is reduced to 14.54 ppm.

After Filter Press, filtrate is the waste water of alkali metal containing salt, for smelting iron washing slag water.After discharge of wastewater, production system replaces salary again.

Before water treatment, system is after the circulation of 35 days, and potassium, sodium salt content=11.3 %, PH=13.4 in water, cyanide content=1380 ppm, has a strong impact on the recovery rate of on-the-spot ore dressing, brings huge challenge to Environmental Protection at Steel Works work.After water treatment, solve this problem preferably.From theory calculate, it is 24.84 tons according to the account form dosages of 60 times.

To water quality cyanide and adding of agent situation as table 2.

Table 2 water treatment procedure adding of agent situation

Embodiment 2: the integrated conduct method of blast furnace gas dry type bag-type dust ash

4# blast furnace dedusting ash Main Ingredients and Appearance content is as table 3.

Table 3 4# blast furnace dedusting ash Main Ingredients and Appearance content detection

Treatment process steps is:

(1) ash is unloaded: 4# blast furnace dry method ash 20 t are put into material pond and exist side by side and namely use recirculated water immersion treatment.

(2) stir: use 5t clamshell crane to grab 5 buckets and put into the agitator that diameter is 2.5m, in agitator, add water 2.2 m deeply, being configured to pulp density is 23.18 %, stirs for subsequent use after 15 minutes.

(3) ball milling: the ore pulp after stirring enters ball mill and carries out ore grinding, makes bulk lump and coarse particulate matter obtains grinding dispersion, is convenient to the ore dressing resolution ratio of follow-up flotation and gravity separation technology.

(4) flotation: ore pulp enters 4A flotation device after ball mill, according to ore pulp after mineral grain fully disperses: floating agent: diesel oil=92: the ratio of 1.08: 0.43 carries out stirring reaction, utilize 4A flotation device to carry out selecting carbon, the carbon content after flotation device flotation is 83.5%.

(5) gravity treatment: select the ore pulp after carbon to utilize the heavy physical property of iron compound to adopt spiral chute and shaking table to carry out gravity separation, the Iron concentrate obtained containing full iron 54.6% is recycled for sintering.

(6) water treatment: regularly add ferrous sulfate according to the amount of 60 times of cyanide ion concentration, total cyanogen is reduced to 12.37 below ppm.

After Filter Press, filtrate is the waste water of alkali metal containing salt, for smelting iron washing slag water.After discharge of wastewater, production system replaces salary again.

Before water treatment, system after the circulation of 32 days, potassium, sodium salt content=13.2 %, PH=12.7 in water, cyanide content=1125.3ppm.

To water quality cyanide and adding of agent situation as table 4.

Table 4 water treatment procedure adding of agent situation

Claims (1)

1. the integrated conduct method of blast furnace dry type dedusting ash, described dedusting ash main component comprises TFe=15% ~ 25%, C=14% ~ 30%, Zn=4% ~ 6%, alkali metal salt=5% ~ 7%, cyanide=0.5% ~ 1.9%, SiO ₂=8% ~ 10%, Al ₂o ₃=2% ~ 3%, CaO+MgO=15% ~ 21%, all the other are a small amount of Pb, Cu chemical combination state or simple substance, it is characterized in that processing step is:

(1) ash is unloaded: dry method ash unloads ash and puts into material pond and exist side by side and namely use recirculated water immersion treatment;

(2) stir: add water dry method ash the mud dispersed with stirring being configured to 20% ~ 30% concentration;

(3) ball milling: the ore pulp after stirring enters ball mill grinding, makes caking and coarse particulate matter obtain grinding dispersion;

(4) flotation: according to ore pulp after mineral grain fully disperses: floating agent: diesel oil=90 ~ 100: the ratio of 1 ~ 1.2: 0.35 ~ 0.45 stirs, utilize flotation device to be sorted out by carbon wherein, what obtain carbon containing > 75% utilizes carbon;

(5) gravity treatment: select the ore pulp after carbon to adopt spiral chute and shaking table to carry out gravity separation, the Iron concentrate obtaining iron content 45% ~ 50% is recycled for sintering;

(6) water treatment: regularly add ferrous sulfate according to the amount of 50 ~ 70 times of cyanide ion concentration in water system, total cyanogen is reduced to 15 below ppm.