CN-116694920-B - Resource utilization method for potassium-containing metallurgical solid waste

Abstract

The invention provides a resource utilization method of potassium-containing metallurgical solid waste, and discloses a resource utilization method of potassium-containing metallurgical solid waste, which comprises seven steps of ash transportation and storage, pulping, leaching, filtering, decarbonizing, water treatment, water storage and irrigation. The invention has the advantages that the potassium removal rate after the treatment of the potassium-containing metallurgical solid waste can reach more than 95 percent, the sodium removal rate can reach more than 89 percent, the leaching slag is recycled in the sintering process of the metallurgical industry, the alkali content of the sintering ore is reduced, the iron-making production efficiency of the blast furnace is improved, and the low-cost recovery and the effective utilization of potassium resources in the potassium-containing metallurgical solid waste are realized.

Inventors

• WANG YONGGANG
• LI JINGLUN
• WANG HONGPING
• LI BOCHAO
• WANG HONG
• HE YUE
• GUO YI
• BIAN LIGUO
• Chi Yongqin
• WANG XIN

Assignees

• 酒泉钢铁(集团)有限责任公司

Dates

Publication Date

20260505

Application Date

20230614

Claims (5)

1. 1. A resource utilization method of potassium-containing metallurgical solid waste is characterized by comprising the following steps: Transporting and storing ash, namely transporting the dust-removing ash by adopting a tank truck, and then transporting the dust-removing ash in the tank to a high-position ash receiving bin by adopting a pneumatic negative pressure conveying device, wherein a flat gate and a double-pipe spiral scale are arranged at the bottom of the ash receiving bin, and the volume of the ash receiving bin can accommodate 165-330 tons of solid waste containing potassium; Step two, slurry is produced, namely a flat gate at the bottom of an ash receiving bin is opened, the dedusting ash is quantitatively fed into a stirring barrel at a speed of 30-50t/h through a double-pipe spiral scale, a new water supply valve is opened, the slurry production water supplementing quantity is measured through an electromagnetic flowmeter, the flow rate is 90-150m 3 /h, and the liquid-solid ratio of water to ash is 3-5:1; step three, leaching, namely conveying the mortar into a mechanical stirring thickener through a pump to fully leach, adding 15-20g/t of carboxymethyl cellulose potassium flocculant to accelerate sedimentation of solid particles, and removing part of Ca 2+ 、Mg 2+ ions to ensure that the concentration of suspended matters in the leaching liquid is less than or equal to 100mg/L; Step four, filtering, namely dehydrating leaching residues by adopting filtering equipment, recycling the dehydrated water to prepare slurry, and returning filter cakes to sintering for recycling; Step five, decarbonizing, namely conveying the leaching solution into 450 m 3 decarbonizing tanks, introducing air into the bottoms of the decarbonizing tanks by using a blower, discharging carbon from overflow weirs of the decarbonizing tanks, filtering and dehydrating the leaching residues, and returning the leaching residues to sintering for use; Step six, delivering the decarbonized leaching solution to a 400m 3 sedimentation tank, adding 5-7g/m 3 polyaluminium ferric chloride (PAFC) to remove heavy metal ions such as iron, manganese, lead and zinc in water, adding 4-6g/m 3 Polyaluminium Ferric Chloride (PFCS) to decolorize, deoil, degerming and reduce COD and BOD in water, adding 2400-3600g/m 3 sulfuric acid to adjust the pH value to 7-8, filtering and dehydrating the solid in the sedimentation tank and leaching residues, and returning to sintering for recycling; and seventhly, storing and irrigating water, namely conveying the water which reduces heavy metal ions, BOD and COD and contains potassium chloride to a reservoir for storage by adopting a pump, and irrigating farmlands and orchards.
2. 2. The method for recycling potassium-containing metallurgical solid waste according to claim 1, wherein the number of leaching stages in the third step is 1 to 3.
3. 3. The method for recycling potassium-containing metallurgical solid waste according to claim 1, wherein the flocculant in the third step is potassium carboxymethyl cellulose.
4. 4. The method for recycling potassium-containing metallurgical solid waste according to claim 1, wherein the mechanical stirring thickener used in the third step is selected from a peripheral drive thickener, a center drive thickener and a deep cone thickener.
5. 5. The method for recycling potassium-containing metallurgical solid waste according to claim 1, wherein the filtering device in the fourth step is a box filter, a plate-and-frame filter press or a press filter.

Description

Resource utilization method for potassium-containing metallurgical solid waste Technical Field The invention belongs to the technical field of metallurgical engineering, and relates to a resource utilization method of potassium-containing metallurgical solid waste. Background Blast furnace ironmaking is developed and improved from ancient shaft furnace ironmaking. The method has the advantages of good technical and economic indexes of blast furnace ironmaking, simple process, large production quantity, high labor productivity and low energy consumption, and the iron produced by the method accounts for more than 95% of the total world iron yield. During the production of blast furnace, iron material, coke and flux (limestone) for slag formation are charged from the top of the furnace, and preheated air is blown from the tuyere located at the lower part of the furnace along the furnace periphery. Carbon in coke (auxiliary fuel such as coal dust, heavy oil, natural gas and the like is also injected into a blast furnace) at a high temperature and oxygen in the air is blown into the blast furnace to burn carbon monoxide, and oxygen in iron materials is removed in the ascending process of the furnace, so that iron is obtained through reduction. And discharging the melted iron from the iron notch. Non-reducing impurities in the iron ore are combined with fluxes such as limestone to form slag, and the slag is discharged from a slag hole. The produced gas is led out from the furnace top and is used as fuel for hot blast stoves, heating furnaces, coke ovens, boilers and the like after dust removal. The alkali metal in the blast furnace ironmaking process is mainly K, na, and because the behaviour of Zn in the blast furnace is similar to that of K, na, zn is also divided into the alkali metal range in actual production, and the content of the alkali metal and the zinc in the furnace in production is generally the content of ton iron K 2O、Na2 O, znO, and the content is expressed by kg/t. With the development of the oxygen-enriched coal injection technology, the actions of reducing agent, heating agent and carburization of coke are partially replaced by coal powder injection, but the coke is used as a material column framework, so that good air permeability of the material column in the blast furnace smelting process is maintained and can not be replaced, and the effect of the coke as the material column framework is directly related to the running state and economic and technical indexes of the blast furnace. The alkali metal has a pulverization effect on the coke, the higher the alkali metal is, the more serious the pulverization of the coke is, so that the action of a material column skeleton of the coke is weakened, the material air permeability is poor, the heat transfer and mass transfer in the high-temperature metallurgical process are seriously affected, the smelting energy of a blast furnace is reduced, the alkali metal is extremely easy to cause the rising of a soft melting belt of the blast furnace, the indirect reduction is unfavorable to develop, the coke ratio is raised, in addition, the alkali metal oxide at the upper part of the blast furnace is adhered to a furnace wall, the furnace wall is promoted to be thick and connected with a tumor, the tuyere and refractory materials of the blast furnace are damaged, and the service life of the blast furnace is shortened. The sintering is a raw material preparation stage of blast furnace ironmaking, which is a process of mixing various powdery iron-containing raw materials with proper amount of fuel and flux, adding proper amount of water, mixing and pelletizing, and then making the materials undergo a series of physical and chemical changes on sintering equipment to bond mineral powder particles into blocks. The sintering temperature of the sinter is 1200-1300 ℃, the melting point of the sylvite is lower than 800 ℃ and the boiling point is about 1400 ℃, so that under the condition of high temperature and negative pressure of the head of the sintering machine, the boiling point of the sylvite is reduced, gasification is aggravated, and the sylvite enters a dust removal system in a gaseous form together with the head ash to be concentrated in the head ash after being cooled. The method has the advantages that the method mainly utilizes the characteristic that both Kcl and Nacl are easily dissolved in water, potassium-containing solution is obtained through a leaching method, and then the potassium fertilizer is prepared through an evaporation process, so that the process cost is high, the method is mainly in a technical research stage, and the industrialized application is less. Disclosure of Invention Aiming at the current situation that the iron and steel metallurgy enterprises in China have high cost for extracting the agricultural potassium chloride and potassium fertilizer by adopting a leaching and evaporation method and are difficult to operate industrially