31results about How to "Reduce molybdenum content" patented technology

The invention discloses a method for preparing a molybdenum-containing additive and carbon disulfide by vacuum carbon thermal reduction of a molybdenum concentrate and belongs to the field of material preparation. According to the method disclosed by the invention, as raw materials, the molybdenum concentrate and carbon powder are proportioned according to a target ratio, are fully mixed and are subsequently treated at the temperature of 1200 to 1700 DEG C and at a vacuum degree of 1 Pa to 1000 Pa by adopting a vacuum carbon thermal reduction method to prepare an molybdenum-containing steel smelting additive of which the molybdenum content is as high as 90%; besides, a volatile product carbon disulfide is prepared; and the carbon disulfide is an important chemical raw material and is collected after being condensed. The method disclosed by the invention is free of generation of polluting gas sulfur dioxide and other pollutants, can be used for preparing the molybdenum-containing steel smelting additive and can also be used for preparing the carbon disulfide which has an extremely high value.

A method for volatilizing and enriching molybdenum from molybdenum tailings relates to a process for utilizing the molybdenum tailings for enriching and recovering the molybdenum. The molybdenum tailings are firstly ground, and the water content thereof is regulated to 30-40%WT to lead the molybdenum tailings to form slurry of the molybdenum tailings. Then, hydrofluoric acid is added in the slurry of the molybdenum tailings, hydrochloric acid is further added after the bubbles disappear and the reaction is complete; after that, the slurry of the molybdenum tailings is heated to 200-250 DEG C, a cover is used for thermal insulation for 30-50min to promote the formation of chloride of the molybdenum, then the cover is removed, and the drying is carried out at 65 DEG C. Finally, the thermal treatment of the molybdenum tailings after the pretreatment with the acid is carried out at 900 DEG C, thereby generating flue gas containing the molybdenum and silicon tetrafluoride and the residues of the thermal treatment, and the residues are used as road-building materials; the collected flue gas is condensed; when the temperature is lower than 250 DEG C, substances containing the molybdenum or molybdenum compounds are recovered; the silicon tetrafluoride in the flue gas is absorbed and hydrolyzed by using water, the filtration is carried out, and filtrate is fluorosilicic acid solution. The process of the invention is simple and easy to control, the products during the process can be recovered, the cost is low, the method has no environmental pollution, and the high temperature volatilization rate of the molybdenum achieves 70 percent-98.6 percent.

The invention discloses a high-activity propylene gas-phase epoxidation catalyst, TiO2-MoO3-Bi2SiO5 / SiO2, for preparing propylene oxide and a preparation method thereof. The catalyst is used for a propylene gas-phase epoxidation reaction for preparing the propylene oxide, which takes molecular oxygen (O2) or nitric oxide (NO) as an oxidant; reaction conditions are moderate and no inhibitor is needed; the catalyst has high catalytic activity. The catalyst takes a SiO2 mesoporous material Bi2SiO5 / SiO2 containing bismuth silicate (Bi2SiO5) as a carrier, MoO3 as an active component and TiO2 as an auxiliary agent. The catalyst comprises following components in percentage by mass: 64.6%-98.8% of the carrier Bi2SiO5 / SiO2, 1.1%-22.8% of the MoO3 and 0.1%-12.6% of the TiO2. The mol ratio of Si to Bi in the carrier Bi2SiO5 / SiO2 is 30-200. The catalyst is synthesized by using a hydrothermal method; molybdenum and titanium precursors in the active component MoO3 and the auxiliary agent titanic oxide are immersed into the carrier by an ultrasonic-assisted immersion method to prepare the catalyst.

The present invention relates to a screening method for molybdenum concentrate, aiming at solving the problems of low resource utilization rate and low recovery rate of molybdenum concentrate in the screening method of molybdenum concentrate in the prior art. The method comprises the following steps: (1) Molybdenum raw ore pretreatment Treatment: Molybdenum raw ore is processed to obtain fine ore; (2) Grinding and grading: Grinding the fine ore to obtain the grinding product, and then passing through the closed-circuit classification of the hydrocyclone to obtain the overflow; (3) Flotation: Add flotation agents to the overflow after grinding and grading, and get rough concentrate through molybdenum ore roughing and dense classification; (4) selection: the rough concentrate obtained in step (3) is passed through After the regrinding process, it enters into the selection process, and after two selections and three sweeps, the molybdenum concentrate is obtained. (5) Concentrate dehydration: Molybdenum concentrate is concentrated and then further squeezed and dehydrated to obtain finished molybdenum concentrate. The screening method of the present invention has high utilization rate of raw molybdenum ore resources, produces less waste residue and waste dust in the screening process, and is friendly to the production environment.

The invention belongs to the field of hydrometallurgy, and relates to a method for leaching and recovering molybdenum from low-molybdenum ammonia leaching residues. The method specifically comprises the following steps that S1) the ammonia-impregnated low-molybdenum ammonia leaching residues are dehydrated and slurried for use; S2) the slurried low-molybdenum ammonia is added into a reaction kettle, pressurized and heated, and a pressure-maintaining reaction is performed to obtain a reaction solution and molybdenum slag; S3) the reaction solution is separated from the molybdenum slag, negativepressure concentration is carried out on the reaction solution, and acid precipitation filtration is carried out on the concentrated solution to form a molybdate filter cake; and S4) the filter cakereturns to the ammonium molybdate production process, and an ammonium molybdate product meeting the GB / T3460-2017MSA-1 level is produced. The method has the beneficial effects that due to the adoptionof the technical scheme, the process is simple and feasible, the ammonia leaching residues do not need to be dried and ground, the process is short, the technology is stable, the production cost is low, the leaching recovery rate is not lower than 94.98%, and the whole technological process is environmentally friendly.

A mold material having a material hardness higher than 340 HB and a fine-grain structure. The mold material having a composition in weight percent that includes:C=0.25-0.35Si=0.04-0.20Mn=1.00-2.00Cr=1.00-2.00Ni=0.30-less than 0.90Mo=0.30-0.80V=less than / equal to 0.20Al=0.01-0.03N=0.0025-0.0150S=less than 0.15a remainder of Fe and impurities.

The invention discloses a method for lixiviating molybdenum from roasted molybdenite. The method comprises the following steps of: 1, uniformly mixing the roasted molybdenite, ammonium carbonate and deionized water at a certain mass ratio, and then stirring for 40-70 minutes under the condition that the temperature is 70-90 DEG C to obtain a turbid liquid; 2, filtering to obtain a filter cake and filter liquor; 3, washing the filter cake by adopting ammonia water, then uniformly mixing the washed ammonia water with the filter liquor to obtain a mixed liquor; 4, regulating the pH value of the mixed liquor to 8.0-8.5, uniformly stirring, then carrying out sedimentation treatment, and taking a supernatant to obtain molybdenum lixivium. The process disclosed by the invention is simple, easy to operate, high in repeatability and suitable for large-scale industrial production, adopts the ammonium carbonate as a lixiviant, and can be used for greatly reducing the sludging ratio and the molybdenum content of dregs by regulating and optimizing the lixiviating process, and achieving the molybdenum lixiviating rate as high as more than 98%.

The invention discloses a method for preparing a molybdenum-containing additive and carbon disulfide by vacuum carbon thermal reduction of a molybdenum concentrate and belongs to the field of material preparation. According to the method disclosed by the invention, as raw materials, the molybdenum concentrate and carbon powder are proportioned according to a target ratio, are fully mixed and are subsequently treated at the temperature of 1200 to 1700 DEG C and at a vacuum degree of 1 Pa to 1000 Pa by adopting a vacuum carbon thermal reduction method to prepare an molybdenum-containing steel smelting additive of which the molybdenum content is as high as 90%; besides, a volatile product carbon disulfide is prepared; and the carbon disulfide is an important chemical raw material and is collected after being condensed. The method disclosed by the invention is free of generation of polluting gas sulfur dioxide and other pollutants, can be used for preparing the molybdenum-containing steel smelting additive and can also be used for preparing the carbon disulfide which has an extremely high value.

The invention discloses a method for reducing molybdenum content after chamber maintenance, comprising step S1, chamber maintenance, wherein the chamber maintenance step at least includes a cleaning step, the cleaning step injects a first process gas, and discharges the first process gas. A process gas is used to reduce the content of metal impurity ions in the chamber, and the cleaning step is repeated for several times; step S2, the detection of the molybdenum content in the chamber is used to measure the content of molybdenum ions in the chamber; step S3, molybdenum element cleaning , in order to reduce the content of the molybdenum ions in the chamber.

The invention discloses a high-temperature-resistant silicon-molybdenum-ferrite nodular cast iron for steam turbines and a preparation process thereof. The nodular cast iron is composed of 3.0-3.5% C, 2.8-3.2% Si, Mn<0.2%, P<0.040%, S <0.015%, 0.5-0.8% Mo, Re<0.010%, 0.040-0.055% Mg, 0.004-0.008% Sb, and the remainder is iron and residual elements. The preparation process includes: burden ratio; melting in an intermediate frequency induction furnace; spheroidization treatment, adding ferrosilicon for primary inoculation; controlling the content of each element; pouring into a plug sprue box for secondary inoculation; pouring molding. The ductile iron obtained by the present invention has better overall performance and lower cost, its spheroidization rate reaches more than 80% specified in GB / T9441-2009 "Metallographic Examination of Ductile Iron", and the ferrite content is greater than 90%. The mechanical properties meet the requirements of production.

The invention discloses a method for separating tungsten and molybdenum, which comprises the following steps: S1, performing primary evaporation and crystallization on a feed liquid containing tungsten and molybdenum, and obtaining primary mother liquor and primary crystalline ammonium paratungstate after primary filtration; S2, performing secondary evaporation on primary mother liquor Crystallization, after secondary filtration, secondary mother liquor and secondary crystalline ammonium paratungstate are obtained; S3, the secondary mother liquor obtained in step S2 is subjected to tungsten and molybdenum separation; S4, the secondary crystalline ammonium paratungstate obtained in step S2 is calcined into yellow After tungsten, at least a part of yellow tungsten is added to the feed liquid in step S1; S5, after the primary crystalline ammonium paratungstate obtained after adding the yellow tungsten of step S4 in step S1 is calcined into yellow tungsten, the obtained yellow tungsten is dissolved. In concentrated ammonia water, the ammonia-dissolved second-stage liquid is obtained. According to the tungsten and molybdenum separation method of the present invention, the tungsten and molybdenum ratio in the evaporative crystallization high-molybdenum paratungstate ammonium paratungstate is increased by two evaporation crystallizations, the proportion of molybdenum entering the subsequent molybdenum removal system is reduced, and the subsequent molybdenum removal cost is reduced.

The invention provides a commercial molybdenum oxide ammonia leaching technology capable of reducing slagging rate and molybdenum content in slag. The commercial molybdenum oxide ammonia leaching technology comprises the following steps: 1, uniformly mixing commercial molybdenum oxide, ammonium water and deionized water in certain proportions so as to obtain turbid liquid, and then stirring the turbid liquid at the temperature of 60-70 DEG C till the pH value of the turbid liquid is 6.5-7.0; 2, filtering so as to obtain filter cakes and filtrate; and 3, washing the filter cakes by adopting the ammonia water, placing the washed filter cakes in a drying cabinet so as to be dried, naturally cooling to obtain ammonia leaching slag, and uniformly mixing the ammonia water after washing and the filtrate in the step 2 so as to obtain an ammonia leaching solution. The commercial molybdenum oxide ammonia leaching technology is simple and practicable, has strong repeatability and is suitable for large-scale industrial production; the reducing slagging rate and molybdenum content in slag are substantially reduced after the ammonia leaching treatment is carried out by adopting the commercial molybdenum oxide ammonia leaching technology.

A method for volatilizing and enriching molybdenum from molybdenum tailings relates to a process for utilizing the molybdenum tailings for enriching and recovering the molybdenum. The molybdenum tailings are firstly ground, and the water content thereof is regulated to 30-40%WT to lead the molybdenum tailings to form slurry of the molybdenum tailings. Then, hydrofluoric acid is added in the slurry of the molybdenum tailings, hydrochloric acid is further added after the bubbles disappear and the reaction is complete; after that, the slurry of the molybdenum tailings is heated to 200-250 DEG C,a cover is used for thermal insulation for 30-50min to promote the formation of chloride of the molybdenum, then the cover is removed, and the drying is carried out at 65 DEG C. Finally, the thermal treatment of the molybdenum tailings after the pretreatment with the acid is carried out at 900 DEG C, thereby generating flue gas containing the molybdenum and silicon tetrafluoride and the residues of the thermal treatment, and the residues are used as road-building materials; the collected flue gas is condensed; when the temperature is lower than 250 DEG C, substances containing the molybdenum or molybdenum compounds are recovered; the silicon tetrafluoride in the flue gas is absorbed and hydrolyzed by using water, the filtration is carried out, and filtrate is fluorosilicic acid solution. The process of the invention is simple and easy to control, the products during the process can be recovered, the cost is low, the method has no environmental pollution, and the high temperature volatilization rate of the molybdenum achieves 70 percent-98.6 percent.

The invention discloses a method for extracting and removing molybdenum from a tungstate solution. The method adopts two-stage sulfuration-solvent extraction to achieve deep purification of high-content molybdenum. Through the first stage of sulfidation treatment, most of the molybdenum in the solution is quickly converted into dithiomolybdate and trithiomolybdate, and then most of the molybdenum in the solution is extracted to the organic phase through a stage of extraction; the remaining small amount of molybdenum in the solution is passed through In the second stage of deep vulcanization, the molybdenum is further transformed into tetrathiomolybdate with stronger affinity with the extractant, and then the excess vulcanizing agent after vulcanization is removed and recycled by vacuum volatilization; after vacuum desulfurization treatment Solution, the molybdenum is deeply removed by two-stage extraction to obtain a purified solution. The invention has high utilization rate of the vulcanizing agent, low total consumption, less consumption of oxidant in the process of organic phase extraction, remarkably alleviates oxidation exothermic phenomenon, and is beneficial to prolonging the service life of the organic phase. There is no waste residue in the whole process of molybdenum removal, which can realize the deep molybdenum removal of high molybdenum solution.

The invention discloses a nickel-molybdenum-copper alloy, which is an alloying agent used for smelting pipe line steel, stainless steel and special steel. The alloy comprises: 20 to 45 percent of nickel, 1 to 8 percent of molybdenum, 18 to 50 percent of copper, less than 0.5 percent of carbon, less than 0.05 percent of sulfur, less than 0.05 percent of phosphorus, less than 2.0 percent of siliconand the balance of ferrum. The alloy can be put at one time during the smelting of the pipe line steel and the like and reduce the labor intensity of smelters.

A mold material having a material hardness higher than 340 HB and a fine-grain structure. The mold material having a composition in weight percent that includes:C=0.25-0.35Si=0.04-0.20Mn=1.00-2.00Cr=1.00-2.00Ni=0.30-less than 0.90Mo=0.30-0.80V=less than / equal to 0.20Al=0.01-0.03N=0.0025-0.0150S=less than 0.15a remainder of Fe and impurities.