35results about How to "Improve green pellet strength" patented technology

The invention discloses a method for preparing an active mixed material through a belt type roasting machine pelletizing method. The method comprises the following steps: (1) crushing and grinding ore; (2) burdening and uniformly mixing: fully and uniformly mixing the coal gangue subjected to fine grinding, a composite additive and water in an intensive mixer according to predetermined proportion,and fully wetting the materials; (3) pelletization: preparing pellets with preset granularity from the uniformly mixed ores; (4) roasting by a belt type roasting machine: distributing the pellets onthe belt type roasting machine, and drying, preheating, oxidizing and roasting, soaking and cooling the pellets; and (5) crushing and fine grinding: crushing and fine grinding the coal gangue pellet material to a set specific surface area to obtain the active mixed material. The invention provides a method for preparing the active mixed material through the belt type roasting machine pelletizing method. The method is suitable for large-scale production, the usage amount of the coal gangue reaches 85% or above, the coal gangue stockpiling problem can be thoroughly solved, and a high-quality mixed material is provided for the construction industry.

The invention belongs to the field of comprehensive utilization of metallurgical residue resources and specifically relates to a preparation method of low-temperature solidified metallurgical pellets.In order to solve the problems that when steel and iron scrap powder are adopted for making pellets, the generated pellets are poor in forming performance, low in sintering intensity, likely to be pulverized and the like. The provided preparation method of the low-temperature solidified metallurgical pellets includes the following steps of a, taking and weighing vanadium titano-magnetite concentrates, steel and iron scraps and a compound bonding agent according to a mass ratio of (28-65):(34-68):(2-4), adding water, uniformly mixing the mixture, and conducting pelleting to obtain raw pellets;b, drying the raw pellets obtained in step a until the moisture content is lower than or equal to 1%, and obtaining dry pellets; c, preheating the dry pellets and conducting sintering to obtain finished pellet products. The preparation method is simple in operation, the prepared pellet products are high in strength, MFe of the finished pellet products is 55-58%, the compressive strength of each pellet is 2,600-3,100 N, the drum index is 90.0-93.5%, and the production cost is low. The new method is provided for comprehensive utilization of the steel and iron scrap powder, and obvious economicbenefits are obtained.

The invention provides a preparation method of a zinc-containing dust pellet. The preparation method comprises the following steps of S1, carrying out burdening , mixing the blast furnace cloth bag ash, the steel-making ladle furnace ash, the steel-making converter smoke dust and other zinc-containing dust with the carbon-containing fine powder to obtain a mixture; S2, carrying out pretreatment, adding water into the mixture obtained in the step S1 for wetting, and piling up and curing after wetting; S3, adding a composite binder into the cured mixture, and carrying out uniformly mixing to obtain a uniform mixture; S4, carrying out pelletizing on the uniformly mixed material prepared in the step S3 to obtain a green pellet; and S5, drying the green pellet in the step S4 to obtain the zinc-containing dust dry pellet. The dry pellet has the advantages of high compressive strength and good reducibility, the metallization rate is high in the direct reduction process, the dezincification effect is good, and the preparation method solves the technical problems that an existing zinc-containing dust pellet is easy to break and pulverize in the reduction process.

The invention discloses a high-silica magnesian fluxed pellet for a blast furnace and a production method of the high-silica magnesian fluxed pellet. The high-silica magnesian fluxed pellet comprises, by mass fraction, 3.5%-5.5% of SiO2, 1.5%-2.2% of MgO, 0.8%-1.2% of basicity, not larger than 1.5% of Al2O3, not larger than 0.1% of K2O and Na2O, not larger than 0.02% of Zn, not larger than 0.05% of S and not larger than 0.07% of P. The silica content of the pellet is high, the pellet can be produced through high-silica iron fine powder, the using proportion of the pellet in the blast furnace is improved, meanwhile, the using scope of the iron fine powder is enlarged, and the using proportion of the iron fine powder inland is improved. By means of the method, the high-silica iron fine powder can be used for producing the magnesian fluxed pellet, the production cost is reduced, meanwhile, the pellet qualified in quality can be obtained, and requirement of the blast furnace for using the high proportion of pellet is met; and by means of the method, the scope of the iron fine powder used for producing the magnesian fluxed pellet can be expanded, and the using amount of the high-silica iron fine powder inland can be particularly improved. The method has the beneficial effects of being low in production cost, simple in process and excellent in product performance.

The invention discloses a method for improving pelletizability of low-pelletizability iron concentrate, which comprises the following steps: adding a small amount of soluble metal salt modifier into the iron concentrate, evenly mixing, adding a small amount of sodium humate into the iron concentrate, carrying out wet grinding pretreatment, and pelletizing. The method is simple to operate and low in facility requests, can effectively enhance the drop strength and compression strength of the iron concentrate crude pellets, enables the other properties to reach the standard, and enhances the iron grade of the finished pellets. The method is especially suitable for pelletizing the low-pelletizability iron concentrate, and can obviously improve the pellet quality of the low-pelletizability iron concentrate.

The invention discloses a method for extracting valuable elements from jarosite slag. The method specially includes the steps of pelletization, oxidation roasting desulfurization, direct reduction, smelting separation, ingot casting, electrolysis and the like. A special additive agent disclosed by the invention is adopted in the pelletization process, and the additive agent comprises an organic binder, an alkaline earth metal source, an alkaline metal source, carbonaceous fuel and iron oxide. By the adoption of the method, by means of extensive research and test certification, the additive agent is used so that pelletization can be enhanced, the roasting desulfurization and consolidation effect of pellets is improved, the strength of the roasted pellets is enhanced, the reducibility of the roasted pellets is improved, the reduction swelling rate of the pellets is lowered, the mobility of the slag is improved, desulfurization capacity of the slag is also improved, and the subsequent process is matched to achieve efficient separation and extraction of the various valuable elements like iron, gallium, zinc, indium and sulfur.

The invention discloses a composite functional material capable of synchronously removing nitrogen and phosphorus and a preparation method thereof, belonging to the field of in-situ remediation of surface water. The preparation method comprises the following steps: mixing a powdery nitrogen adsorption component, a permeation component, a bonding component and a rare earth component to obtain a mixture, wherein the mass ratio of the rare earth component in the mixture is 0.5-5%; and granulating the mixture in a granulator, and conducting calcining to obtain a finished filter material. By addingthe rare earth component, the problem that other biological curing materials are not obvious in phosphorus adsorption effect is solved, so synchronous adsorption of nitrogen and phosphorus is achieved; and the finished filter material can be used for synchronous treatment of inorganic nitrogen and soluble phosphorus in surface water, so the problem of nitrogen and phosphorus pollution is effectively solved.

The invention belongs to the technical field of non-blast furnace ironmaking and discloses a method for gas-based direct reduction for iron ore powder. The iron ore powder and a carbon-based additiveare mixed evenly and are bonded into pellets through a binder, then drying treatment is conducted, the dried pellets are reduced, wherein the ratio of carbon in the carbon-based additive to oxygen atoms in the iron ore powder is 0.1-0.4, the reduction temperature is 980-1080 DEG C, and reduction time is 1-1.5 h. The method is easy to control and low in energy consumption, the reduction time is reduced, and productivity is improved. The carbon-based additive is added into the pellet raw materials, thus the reduction temperature is controlled to 980-1080 DEG C, pores can be formed in the pellets, the contact area of reduction gas and iron oxide is increased, conversion efficiency of the reductive gas is enhanced, and the gas-based direct reduction reaction rate is effectively increased. Meanwhile the method has the characteristics that pollution is avoided, and the product cleanliness is high.

The invention relates to a production process of organic composite bentonite for metallurgical pellet production. The production process is characterized by comprising the following steps that firstly, sodium modification is conducted on calcium bentonite to obtain a finished product sodium bentonite; a certain amount of organic bonding powder is added into the sodium bentonite to prepare organic composite pellet bentonite; sodium carboxymethyl starch (CMS-Na) and polyacrylamide (PAM) are sufficiently and evenly stirred in a stirrer to prepare organic bonding powder; the sodium carboxymethyl starch (CMS-Na) is organic matter and is a water-soluble anionic high-molecular compound; the polyacrylamide is PAM in short and is the high-molecular-weight sodium bentonite easily dissolved in water, and the sodium bentonite and the organic bonding powder are sufficiently mixed to prepare the organic compound bentonite; when metallurgical pellets are produced, the organic composite bentonite is prepared into slurry according to the certain concentration, and then the slurry is sprayed on metallurgical powder in a pelletizing disc of a rotating pelletizer by using a slurry pump for pelletizing; and the combustion of the organic matter has no influence on the quality of metallurgical products and does not pollute the environment.

The invention discloses a zinc-containing dust hydrogen reduction dezincification method which comprises the following steps: S1, adding water into a zinc-containing dust material for wetting, stacking after wetting, covering, heating and curing to obtain a cured material; s2, a binder is added into the cured material, strong uniform mixing treatment is conducted, then high-pressure roller grinding and wet grinding combined treatment is conducted, and a uniformly mixed material is obtained; s3, pelletizing the uniformly mixed material, and then drying green pellets to obtain dry pellets; and S4, the dry balls are loaded into a gas-based shaft furnace for hydrogen reduction, the reduction temperature ranges from 800 DEG C to 950 DEG C, cooling is conducted under the protective atmosphere after reduction, and the reduced dezincified balls are obtained. According to the method, the advantages of low hydrogen reduction temperature, high reduction rate, low energy consumption, high efficiency and no carbon emission are utilized, the zinc-containing dust pellets are reduced, so that many problems existing in traditional carbon thermal reduction are solved, the reduction effect can be improved, the comprehensive utilization effect of the zinc-containing dust can be improved, and environmental protection is facilitated.