54results about How to "Improved particle size composition" patented technology

The invention relates to a high-pressure rolling and magnetic-gravity separation process for lean hematite. The high-pressure rolling and magnetic-gravity separation process for lean hematite is characterized by comprising the following steps that after raw ore particles with the particle size of 0-300 mm are subjected to the coarse crushing and intermediate crushing screening operation, the product particle size is 0-35 mm; after the particles pass through a high-pressure roll mill and a wind grading system, the large-particle-size products subjected to wind grading return to the high-pressure roll mill, the small-particle-size products subjected to wind grinding and with the 200-mesh sieve sieving rate being 90%-95% are fed to the technical procedures with low intensity magnetism, high intensity magnetism and a centrifugal machine so as to be graded; concentrate obtained through low intensity magnetic separation and concentrate obtained through the centrifugal machine are combined into final concentrate with the grade being 66.5%-67.5% and the yield being 27%-29%; and the grade of tailings of high intensity magnetic separation is 8.3%-8.8%, the grade of tailings of two-stage scavenging centrifuge is 16%-18%, and the tailings of high intensity magnetic separation and the tailings of two-stage scavenging centrifuge are combined into final tailings with the grade being 10.50%-11% and the yield being 61%-63%. The high-pressure rolling and magnetic-gravity separation process for lean hematite has the advantages that original fine crushing operation and two-stage grinding operation are omitted, the products with the 200-mesh sieve sieving rate being 90%-95% can be directly obtained by the adoption of the high-pressure roll mill and the wind grading system, the process structure is simplified, and the ore separation cost is reduced significantly.

The invention relates to a casting-molded large-scale nitride-combined silicon carbide product. The product employs silicon carbide particles and powder, silicon carbide micro powder, silicon dioxide micro powder, alumina micro powder, active magnesium oxide and a water reducer as powder materials, employs silica sol as a binder and is molded by employing vibration casting. A molded blank is subjected to maintenance, drying, and high-temperature nitridation processing in nitrogent, so that the nitride-combined silicon carbide product is prepared. By reacting silicon dioxide and silicon carbide in the materials with nitrogen at the conditions of high temperature and nitrogen, silicon nitride is generated and other nitrides are further generated, and thus the combination strength is generated. The products helps to solve the problems and the disadvantages that conventional nitride-combined silicon carbide products generated through nitridation of silicon powder is high in cost and relatively easily have residual silicon, large-scale products cannot be produced, and the like. According to the technical scheme, the large-scale nitride-combined silicon carbide product can be produced and has the advantages of low cost, excellent performances and the like, the prepared silicon carbide product is capable of replacing conventional Si3N4-combined, Si2N2O-combined and Sialon-combined silicon carbide and being applied to fields of steel industry blast furnace air ports and blast furnace cooling wall cast-in bricks, nonferrous metals industry aluminium electrolytic tanks and the like.

The invention discloses a sintering mixture, a vanadium-titanium sinter prepared from the sintering mixture and a preparation method of the vanadium-titanium sinter. The sintering mixture comprises the following raw materials in percentage by weight: 54-58% of vanadium-titanium-iron concentrate, 2-8% of ordinary iron concentrate, 13-16% of ordinary ore powder, 1-6% of ore-rich powder, 3-5% of medium-sized hematite ore powder, 11-13% of a solvent and 4.5-5.5% of a fuel. The sintering mixture is low in cost; by virtue of the use of the sintering mixture, the sinter ore can be produced at a high yield; the prepared sinter ore is high in strength, high in rate of finished products and excellent in low-temperature reduction pulverization performance.

The invention discloses a mineral separation method for improving high-sulfur magnetite and hematite mixed ore separation indexes. The method comprises the steps that raw ore is subjected to the processes of stage grinding, flotation sulfur separating and low-intensity magnetic separation, low-intensity magnetic separation tailing is discharged, and qualified sulfur concentrate and magnetite concentrate products are obtained; strong magnetic separation is conducted on the discharged low-intensity magnetic separation tailing, high-intensity magnetic separation tailing T1 is discarded, and thena high-intensity magnetic rough concentrate is obtained; the obtained high-intensity magnetic rough concentrate is subjected to fine-sieve sieving work, and a retained product directly serves as tailing T2 to be discarded; and a fine-sieve through product is fed into a spiral chute gravity separation technology, spiral chute gravity separation tailing T3 is discarded, and a spiral chute gravity separation iron concentrate C is obtained, wherein the spiral chute gravity separation technology comprises the primary spiral chute rough separation step and the primary spiral chute fine separation step. The mineral separation method for improving the high-sulfur magnetite and hematite mixed ore separation indexes has the advantages that the grade of hematite concentrate TFe is high, the operationrecovery rate is high, the technological process is simple and easy to carry out, the indexes are stable, and operation and management are easy to achieve on the site.

The invention relates to a high-pressure roller grinding, weak magnet-strong magnet-reverse flotation technology for poor hematite. The technology includes the step that the poor hematite is subjected to rough crushing and medium crushing and is characterized by further including the following steps that after raw ore with the particle size being 300-0mm is subjected to rough crushing and medium crushing screening operations, the product particle size is 35-0mm; by the adoption of a high-pressure roller grinding device and an air classification system, coarse-grained products suffering from air classification return to the high-pressure roller grinding device, and fine-grained products with the air classification particle size being -200 meshes and the content being 90%-95% are fed into the weak magnet-strong magnet-anion reverse flotation technology. By the adoption of the technology, an original fine crushing operation and a two-section ore grinding operation are omitted in the technological process, the high-pressure roller grinding device and the air classification system are adopted so that the fine-grained products with the particle size being -200 meshes and the content being 90%-95% can be obtained directly, the flowage structure is simplified, short-process sorting is realized, beneficiation cost is greatly reduced, and economical benefits are remarkable.

The invention relates to a poor hematite high pressure roller milling, thickness grading and reselection-magnetic separation-centrifugal machine sorting process. The process is characterized in that raw ore passes through coarse breaking, medium breaking screening, high pressure roller milling and air classification systems to be fed into a thickness grading hydrocyclones to be subject to classification operation, reselection, magnetic separation and centrifugal machine sorting are then carried out, and concentrates with the grade ranging from 67.5% to 67.8% and the yield ranging from 31.33% to 32% and tailings with the grade ranging from 10.5% to 11.5% and the yield ranging from 67.5% to 68.5% are sorted. According to the technological process, fine breaking operation in original three-stage breaking and first-stage ore grinding operation are omitted, a product with the granularity being 200 meshes and the content ranging from 60%-65% can be obtained directly through high pressure roller milling and thickness grading, the flowage structure is simplified, short process sorting is achieved, the ore separation cost is greatly reduced, and economical benefits are remarkable.

The invention provides a technological method for recycling fine-particle cassiterite from gravity raw ore. The method is characterized by comprising advanced slurry mixing and grading steps on the gravity raw ore; the advanced slurry mixing and grading steps comprise technologies for carrying out gravity concentration on underflow and carrying out flotation on overflow, and comprise separation of fine-particle slime from the particle capable of being sepatated by a table concentrator; the fine-particle slime is fed to flotation as overflow; the particle capable of being sepatated by the table concentrator is fed to gravity concentration as the underflow. According to the advanced slurry mixing and grading method, effective recovery of the fine-particle cassiterite in the overflow which is subjected to advanced slurry mixing and grading is achieved; the technical problem of recovery of the fine-particle cassiterite is overcome; new idea and exploration direction are provided for ore dressing workers for solving fine-particle cassiterite recovery research; the ore feeding mode of a traditional cassiterite gravity-recovery process is broken through; with respect to the overflow which is subjected to advanced slurry mixing and grading overflow, when the grade of tin in the ore feeding process is 0.75%, the grade of tin concentrate which is obtained by tin flotation is 6.52%, the operation recovery rate is 61.26% and the recovery rate in the ore feeding process is 60.09%.

The invention discloses a sintering method of fine Baima vanadium-titanium magnetite concentrate. The sintering method comprises the sequential steps of burdening, mixing with water, pelletizing, igniting and sintering, spraying CaCl2 solution and blast furnace processing, wherein based on mass, the water content in the mixed material in the water mixing step is 7.2-7.5%; the carbon content in the mixed material is 4.8-5.0%; the material layer height when igniting and sintering is 640-700 mm; and the mass concentration of the sprayed CaCl2 solution is 1.5-3%. Through optimizing of the sintering technical parameters, comprehensively improving of the water content of the sintering mixed material, the carbon content in the mixed material and the height of the material layer, the grain composition and the sinter components of the mixed material when the fine Baima vanadium-titanium magnetite concentrate is sintered are greatly improved; the sintering atmosphere, flux mineralization, sintering heat system and mineral crystallization in the sintering process are effectively strengthened, so as to improve the sinter product yield and quality, and enable the yield and the quality of the sinter and the metallurgical performance to be greatly improved.

The invention discloses a pelletizing method for reducing bentonite consumption. Bentonite is adopted as a binding agent. The pelletizing method comprises the steps of mixing, pelletizing, drying and preheating and roasting. In the step of mixing, a mixture of Qing Gangping concentrate powder with the weight ratio of 50%-70% and XiChang South concentrate powder with the weight ratio of 30%-50% is adopted as pelletizing concentrate powder; and during mixing, water is firstly added to the bentonite to wet the bentonite, and then the bentonite is mixed with the pelletizing concentrate powder to form mixed powder. The bentonite is fully expanded through selective treatment on concrete powder raw materials and control over parameters in the bentonite mixing step, the concentrate power is in full contact with the bentonite, the effective utilization rate of the bentonite is improved, and therefore pelletizing quality is improved.

The invention relates to the metallurgical field, in particular to a recovery method of blast furnace dedusting ash and a blast furnace dedusting ash sintering material. According to the method, the blast furnace dedusting ash and sintering mixing water are mixed, and blast furnace dedusting ash mortar is made. The blast furnace dedusting ash mortar, an iron-containing material, a fluxing agent, fuel and return mine are subjected to mixing granulation, and a mixed material is made; and finally, the mixed material is sintered. The blast furnace dedusting ash mortar is adopted to perform sintering, the mixed material grain composition can be remarkably improved, the proportion of the +3 mm part in the sintered mixed material is increased, an obvious effect is achieved for improving the breathability of a mixed material layer, and therefore the sintering utilizing coefficient is improved, the sintering mine yield is increased, and therefore the utilizing rate of the blast furnace dedusting ash is greatly increased. The blast furnace dedusting ash sintering material made through the recovery method of the blast furnace dedusting ash is good in breathability and high in sintering utilizing rate.

The invention discloses a preparation method of an anti-erosion silica brick for a carbon calcination furnace. Calcined silica materials with different granularities are taken as main raw materials, a combustion aid, a compound additive, an enhancer and a binding agent are added, the raw materials are mulled, pressed, dried, then put into a kiln, and sintered under the thermal insulation condition for 24-30 hours at the temperature of 1,380 DEG C-1,440 DEG C, a finished product is formed and cooled to the normal temperature, and the anti-erosion silica brick is prepared. The high-temperature performance of the product is excellent, the compactness and the yield of finished products are improved, the erosion resistance is improved, and the service life of the carbon calcination furnace is greatly prolonged.

The invention discloses a pelletizing method for improving the particle size of a sintering mixture and belongs to the field of ferrous metallurgy. Dedusting ash is mixed with fine-particle active lime to form a mixture; water is added for slaking; full stirring and slurrying are carried out, the mixture, coarse-particle active lime after slaking through adding water and other sintering materialsare mixed and pelletized to obtain the sintering mixture; the mixing, water adding and slaking process pre-wets the dedusting ash, at the same time, heat released through slaking of the active lime can raise the temperature of dedusting ash particles to increase the water absorption speed, and the the adverse impact of the hydrophobicity of the dedusting ash to sintering pelletizing is compensatedto certain degree. In addition, as the particles of the dedusting ash and the fine-particle active lime are smaller, core particles for pelletizing are not provided, and aggregation after mixing is avoided, slurry uniformity is ensured; and in addition, the active lime after slaking has viscousness and can be adhered to the dedusting ash particles, the pelletizing capacity is improved, and size composition of the sintering mixture is improved to improve the technical-economic indicator of sintered ore.

The invention discloses a metallurgical sintering synergist as well as a preparation method and application thereof. The synergist is prepared from the following raw materials in percentage by weight: 35-65% of steel slag, 0.1-2% of polyethylene glycol, 2-8% of fluorite, 0.05-2.5% of potassium permanganate, 0.5-8% of hydrogen peroxide, 1-5% of ammonium metavanadate, 0.5-2% of waste activated carbon and the balance of water. By optimizing the compound substances and using the synergist, the rotary drum quality of the sintered ore can be improved, the vertical sintering speed can be increased, the particle size composition of the sintered ore can be improved, RDI + 3.15 can be improved, the reduction degree and the molten drop performance can be improved, and the energy consumption can be reduced.

The invention discloses a method for improving the strength and the size composition of a sinter. The method is characterized in that when fluxes are added in a dosing chamber, a brucite fiber accounting for 0.90-0.95 % of the total mass of a sintered material is also added besides a calcium flux and a magnesium flux; after dosing, the brucite fiber, the calcium flux, the magnesium flux, an iron material and fuel are thoroughly mixed, and then water is added to wet the material to be subjected to a sintering process. Under the situation that the neutralized material structure, the fuel ratio and the sinter basicity remain unchanged, the brucite fiber is added, the sintering time is shortened from the original 24.2min to 21.9min, the productivity is increased by 26.6%, the sinter tumbler strength is improved by 9.15%, the average sinter size composition is improved by 2.25mm, the sinter solid fuel is decreased by 8.91kg/t, and the economic benefits are obvious, and the popularization and application values are great.