CN-116751971-B - High-strength biomass carbon-containing pellet and preparation method and application thereof

Abstract

The invention discloses a high-strength biomass carbon-containing pellet, a preparation method and application thereof, and relates to the technical field of blast furnace ironmaking, wherein the pellet comprises the following preparation raw materials in percentage by mass: 70-85% of iron ore, 4-15% of binder, 5-11% of biomass charcoal and 1-3% of alkaline flux. The high-strength biomass carbon-containing pellets have higher strength and better wear resistance, and the high thermal explosion temperature and the smaller thermal explosion index enable the pellets to enter a blast furnace so as to effectively reduce the powder production. The reducibility, the reduction expansibility and the low-temperature reduction degradation performance of the high-strength biomass carbon-containing pellets are superior to those of the traditional sinter, pellet and lump ore, the high-strength biomass carbon-containing pellets can be directly used as blast furnace burden, the consumption of coke in blast furnace smelting is reduced, further the iron-making cost and the CO 2 emission are reduced, and the high-strength biomass carbon-containing pellets have remarkable economic, social and ecological benefits.

Inventors

• YUAN XIANG
• XU YIJUN
• DAN JIAYUN
• ZHENG LIN
• PAN YUZHU
• He Erxi
• WANG GUANGWEI
• NING XIAOJUN

Assignees

• 湖南华菱湘潭钢铁有限公司
• 北京科技大学

Dates

Publication Date

20260505

Application Date

20230710

Claims (5)

1. 1. The preparation method of the high-strength biomass carbon-containing pellets is characterized by comprising the following steps of: S1, mixing preparation raw materials and water to prepare an aqueous mixed material, wherein the preparation raw materials comprise, by mass, 72% -85% of iron ore powder, 4% -15% of binder, 5% -11% of biomass charcoal and 1% -3% of alkaline flux; The binder comprises at least one of cement, bentonite, aluminum dihydrogen phosphate, water glass, gelatinized starch, sodium carboxymethyl cellulose and phenolic resin, wherein the biomass charcoal is at least one of straw pyrolytic charcoal and waste wood pyrolytic charcoal, the volatile component of the biomass charcoal is less than 25%, and the mass ratio of the biomass charcoal with granularity less than 0.074mm is more than 60%; S2, carrying out heat treatment on the water-containing mixed material after high-pressure forming, wherein the heating atmosphere of the heat treatment is an oxygen-free atmosphere, the temperature of the heat treatment is 300-500 ℃, and the time of the heat treatment is 10-100 min.
2. 2. The method of claim 1, wherein the iron ore powder comprises at least one of hematite, magnetite, and limonite.
3. 3. The method according to claim 1, wherein the alkaline flux comprises at least one of limestone, dolomite, slaked lime, light burned dolomite, slaked lime, serpentine, and forsterite.
4. 4. A high strength biomass carbonaceous pellet produced by the production process according to any one of claims 1 to 3, characterized in that the compressive strength of the high strength biomass carbonaceous pellet is greater than 2000N/pellet.
5. 5. Use of the high strength biomass carbonaceous pellets of claim 4 in blast furnace ironmaking production.

Description

High-strength biomass carbon-containing pellet and preparation method and application thereof Technical Field The invention relates to a blast furnace ironmaking production technology, in particular to a high-strength biomass carbon-containing pellet, and a preparation method and application thereof. Background The traditional blast furnace burden mainly takes sinter and pellet as main materials, and the processes of iron oxide reduction and slag iron melting separation occur in the blast furnace, so that the blast furnace massive belt is ensured to have higher porosity and gas permeability, and the stable and smooth operation of blast furnace smelting is realized. However, the sintering ore and the pellet process are carried out under the high temperature condition, a large amount of fossil fuel is consumed, a large amount of pollutants are discharged, and a novel furnace burden capable of replacing the sintering ore and the pellet can be found, so that the novel furnace burden becomes a key for realizing green low-carbon sustainable development in blast furnace ironmaking production. The cold-bonded carbon-containing pellets are pellets which are added with a certain carbon reducing agent, compared with the traditional sintered ore and oxidized pellets, the carbon-containing pellets enlarge the interface of carbon-oxygen reduction reaction, reduce the diffusion of gas at the interface of solid-phase reaction, simultaneously make the carbon-oxygen of the carbon-oxygen-containing pellets directly contact, and inhibit the oxidation of oxidizing gas in the diffusion and discharge process of the gas generated by the reduction reaction. The carbon-containing pellets are effective means for reducing the coke ratio and the fuel ratio and improving the production efficiency in blast furnace smelting. Compared with the sintered ore and the traditional oxidized pellet, the cold-bonded pellet does not need high-temperature sintering or roasting, has the characteristics of simple equipment, short process flow, low construction investment cost and low emission of CO 2 and pollutants, and particularly, the cold-bonded pellet can be agglomerated by adopting iron ore powder and a coal powder reducing agent to prepare an iron-containing material with a certain carbon content, which is difficult to achieve by the traditional sintered ore and oxidized pellet. The traditional cold bonded pellets generally adopt a binder as a main measure for improving the strength of the pellets, and have the problems of high price, large using amount, low consolidation strength, low iron grade, high content of harmful elements and the like, so that how to improve the strength of the cold bonded pellets becomes a key problem for successfully applying the cold bonded pellets to blast furnace ironmaking production. The related art discloses a carbon-containing pellet for a blast furnace, which takes sintering machine head electric precipitation ash, blast furnace gas mud, stokehole ore tank precipitation ash and calcium-free slag as raw materials, bentonite and slaked lime binder are added to prepare the carbon-containing pellet, so that the recycling of wastes is realized, but the content of harmful elements in the pellet is high, the compressive strength is only 96.82N/g, and the carbon-containing pellet is difficult to be applied to blast furnace ironmaking production. The related art discloses a preparation method of iron ore hot-pressed carbon-containing pellets and iron-making raw materials, wherein iron ore powder, coal dust and flux are uniformly mixed and then heated for hot-press forming, and the hot-pressed formed pellets are subjected to long-time heat treatment at high temperature to produce the pellets with compressive strength of more than 2000N/pellet and dropping strength of more than 4 times/pellet. Disclosure of Invention The present invention is directed to a high strength biomass carbonaceous pellet that addresses at least one of the problems and disadvantages set forth in the background art above. The invention also provides a preparation method of the high-strength biomass carbon-containing pellets. The invention also provides application of the high-strength biomass carbon-containing pellets. The invention discloses a high-strength biomass carbon-containing pellet, which comprises the following preparation raw materials in percentage by mass: 70% -85% of iron ore, 4% -15% of a binder, 5% -11% of biomass charcoal and 1% -3% of an alkaline flux, wherein the binder is used for improving the normal temperature and high temperature strength of the carbon-containing pellets, the biomass charcoal is a reducing agent of the iron ore, and the alkaline flux improves the high temperature metallurgical performance of the carbon-containing pellets. According to one of the technical schemes of the high-strength biomass carbon-containing pellets, the biomass carbon-containing pellet at least has the following beneficial effects: The hi