81results about How to "Reduced slag discharge" patented technology

The invention relates to the field of vanadium slag hydrometallurgy and vanadium chemical engineering, in particular to a method for extracting chromium and vanadium from vanadium slag at a low temperature and the normal pressure. The method comprises the following steps that firstly, burdening, wherein the vanadium slag and a NaOH solution are mixed to form reaction slurry; secondly, reaction, oxide gas is led into the reaction slurry through a micro-hole arrangement device to carry out normal-pressure oxidative leaching, and after the reaction, solid-liquid mixed slurry of a solution containing NaOH, Na3VO4, Na2CrO4, water soluble impurity components and iron-rich tailings is obtained; thirdly, solid-liquid separation; fourthly, impurity removing; fifthly, sodium vanadate crystallization; and sixthly, sodium chromate crystallization. According to the method, chromium and vanadium efficient common extraction can be achieved, the extraction efficiency of both chromium and vanadium can be higher than 85%, more importantly, after the micro-hole gas distribution manner is adopted, the oxygen solubility can be obviously improved, the reaction temperature and alkali concentration are obviously reduced compared with those of an existing vanadium extraction method, the operation safety is greatly improved, and reaction energy consumption is reduced.

The invention relates to a method for decomposing vanadium slag with solution of potassium hydroxide under normal pressure, which comprises the following steps: adding the vanadium slag or pre-treated vanadium slag, water and KOH into a reactor, controlling the mass ratio of the KOH to the vanadium slag and the concentration of solution of KOH, performing oxidation reaction in the presence of oxidizing gas, and controlling the reaction temperature and reaction time in the reaction process; diluting the obtained reaction slurry with a diluting agent to obtain mixed slurry which contains potassium hydroxide, potassium vanadium, potassium chromate and tailings; and performing filtering separation on the mixed slurry to obtain the tailings and vanadium and chromium-containing aqueous solution. The method is only operated under normal pressure, is easy to perform and has high safety; the operation temperature is far lower than the traditional vanadium extraction temperature; the extraction rate of vanadium is high; and synchronous extraction of chromium in the vanadium slag can be realized. The total amount of the vanadium in the tailings is 0.2-1 weight percent (based on the amount of V2O5) and the total amount of the chromium is 0.2-1 percent (based on the amount of Cr2O3).

The invention belongs to the field of chromite hydrometallurgy and chromium chemical industry, and in particular relates to a method for the pollution-free production of sodium chromate by pressure leaching of chromite. The method comprises the following steps of: 1) reacting the chromite with oxidizing gas in solution of NaOH; 2) diluting the product obtained by the step 1) and making subcrystalline sodium chromate to fully enter a liquid phase; 3) performing solid-liquid separation on the solid-liquid mixed slurry obtained by the step 2); 4) adding calcium oxide into the obtained diluent for removing impurities; and 5) evaporating and crystallizing the obtained solution without the impurities to obtain a sodium chromate crystal and crystallization mother solution; after the solid-liquid separation, rinsing the sodium chromate crystal by using saturated solution of sodium chromate; and drying to obtain a qualified sodium chromate product. The method has the advantages of simple reaction system component, no difficultly separated phase introduced in the system, contribution to high-efficiency separation of the sodium chromate, great reduction in reaction temperature, low energy consumption, effective reduction in production cost of the sodium chromate, and high chromium leaching yield.

The invention discloses a method for extracting aluminum oxide and silica gel from beauxite (aluminum bauxite). In the method, steps such as cyclic activation, leaching, recovery of carbon, sodium carbonate and water, separation of silicon from aluminum, thermal decomposition and recovery of hydrochloric acid are employed to obtain high-purity aluminum oxide; in addition, CO2 produced in the whole technological process and alkaline, acid and water used in the process of extraction can all be recovered and recycled. The method of the invention features high extraction efficiency of aluminum oxide, simple technological process, high-purity obtained silica gel and major breakthroughs in solving the technical problem that a great deal of waste residue is produced in the process of traditionally extracting aluminum bauxite and deironing is costly.

The invention belongs to the field of preparation of inorganic metal compounds, and particularly relates to a method for preparing rutile-type titanium dioxide. The method for preparing rutile-type titanium dioxide comprises the following steps: 1) adding sulfuric acid into titanium slag to obtain an acid hydrolysate; 2) leaching the acid hydrolysate obtained in the step 1) with dilute sulfuric acid; 3) filtering the titanium solution obtained in the step 2), adding ammonia water into the obtained filtrate, and adding a reducer to obtain a titanium solution in which the TiO2 concentration is 100-130 g/L; 4) hydrolyzing the titanium solution obtained in the step 3), and filtering to obtain a titanium dioxide hydrate solid and a hydrolysis mother solution; and 5) calcining the titanium dioxide hydrate obtained in the step 4) to obtain the rutile-type titanium dioxide. The invention provides a clean production method for producing rutile-type titanium dioxide from low-grade titanium slag, and provides an effective way for comprehensively utilizing titanium resources and preparing titanium dioxide (titanium white).

The invention relates to a normal pressure low temperature leaching production method for alumina comprising the steps of, (1) subjecting the bauxite to extraction reaction in alkaline solution, filtering to obtain queous alkali and slags containing sodium aluminate, (2) subjecting the queous alkali to compression and cooling down for crystallization, filtering to obtain hydrated sodium aluminate coarse-grain and the filtrated stock solution, dissolving the hydrated sodium aluminate coarse-grain with water or diluted alkaline liquor, obtaining aluminum hydroxide through desiliconization operation, and calcining the obtained aluminum hydroxide.

A process for treating the industrial sewage containing Cr and V includes such steps as preparing the solution of sodium pyro-sulfite, proportionally adding it to the sewage in reduction tank, reducing the 6-valence Cr to 3-valence Cr, proportionally adding the solution of sodium hydroxide to the sewage in neutralizing tank for reaction between V2O2 and sodium hydroxide to generate Na2V4O9 * 4H2O, reaction between V4O9 and said 3-valence Cr to generate Cr2(V4O9)3 deposit and changing residual 3-valence Cr to chromium hydroxide deposit, regulating pH=7.5-8.5, clarifying, and press filtering of suspended substance.

The invention belongs to the preparation of inorganic metallic compound and the processing filed of mineral resource, in particular to a preparation method for preparing titanium dioxide (titanium pigment) through high titanium slag and sodium hydroxide without pollution. The invention is characterized in that the high titanium slag is taken as the raw material; the high titanium slag and the potassium hydroxide having temperature range from 350 DEG C to 550 DEG C are reacted to prepare a medium product; the medium product is then washed through water (or carbonatation), acid solubled, reduced, hydrolyzed and burned to prepare anatase or rutile titanium dioxide. The alkali circulation, the acid circulation and the separation technology of the invention greatly reduce the production energy consumption, simplify the production process, reduce the device investment and increase the technology maneuverability, thereby providing an effective method for the comprehensive use of the titanium resource and the preparation of titanium dioxide (titanium pigment).

The invention relates to a clean production process for processing low-grade laterite-nickel ore by a sodium hydroxide alkali fusion method. The process comprises the following steps: taking laterite-nickel ore as a raw material, carrying out roasting reaction on the laterite-nickel ore and sodium hydroxide at high temperature, washing and filtering the roasted material, and leaching valuable metal salts in the laterite-nickel ore, such as water-soluble chromium, aluminium and the like generated after the reaction. High-temperature roasting damages the crystal lattice structure of the laterite-nickel ore, thereby greatly improving the leaching rate of nickel and cobalt in the subsequent high-pressure acid leaching process and the grade of Fe in acid leaching dregs; filtrate is prepared into chromium salt, aluminium salt and recyclable sodium hydroxide by operations, such as evaporation, crystallization, separation and the like, so that the laterite-nickel ore product is diversified. The leaching rate of hexavalent chromium in the laterite-nickel ore is more than 90%, the leaching rate of trivalent aluminium is more than 75%, the leaching rate of the nickel is more than 98%, the leaching rate of the chromium is more than 94%, and the Fe content of fine iron powder in the acid leaching dregs is more than 61%.

The invention discloses a method for producing sodium chromate through calcium-free enriched oxygen or pure oxygen roasting, mainly aims to solve problems that conventional calcium-free roasting rotary kiln production in China and outer countries is relatively low in chromium conversion rate, long in kiln material reaction time, relatively high in roasting temperature and the like, and aims to achieve the purposes that through enriched oxygen roasting (or pure oxygen roasting), the reaction velocity is increased, the chromium conversion rate is increased, the energy consumption is reduced, the waste residue discharge is reduced, the production efficiency is improved and the cost is lowered.

The invention relates to a method for extracting vanadium from a vanadium containing material. The vanadium containing material is sintered, and clinker is obtained; then the clinker is mixed with ammonium salt and stearic acid, the mass ratio of the ammonium salt to the clinker is 1: (1-10), and reaction materials are obtained; and the reaction materials are sequentially subjected to the amination reaction and the deamination reaction, and then vanadium-containing lixivium is obtained. By means of the method, efficient vanadium extraction is achieved, the vanadium extraction rate reaches 95% or above, the usage amount of the ammonium salt is greatly reduced, and the production cost is reduced; and meanwhile the problem of amination material attachment in a roller reactor under the condition of the low liquid-solid ratio is solved. By means of the method, simple and clean separation of vanadium can be achieved, the water consumption amount and the slag discharging amount are reduced, meanwhile, dust and waste gas harmful to people and the environment cannot be generated, the reaction energy consumption is obviously reduced, and industrial popularization is facilitated.

The invention relates to the fields of pulping and papermaking, and concretely relates to a waste paper pulping fine screening tailing treatment technology. The technology comprises the following steps: (1) waste paper pulping fine screening tailings are fed into a transition tank 1, and then goes through a primary fine screen to obtain a primary good pulp and a primary tail pulp, and the primarygood pulp enters a residue remover; (2) the primary good pulp goes through a medium-consistency stand tube 1, and the primary tail pulp is fed into a secondary fine screen to obtain a secondary good pulp and a secondary tail pulp; (3) the secondary good pulp returns to the primary fine screen, and the secondary tail pulp is fed into an end fine screen to obtain a third good pulp and a third tail pulp; (4) the third good pulp returns to the secondary fine screen, the third tail slurry is fed into a transition tank 2, and then is sequentially processed by a fluffer, a medium-consistency stand tube 2 and a flotation tank to obtain a fourth good pulp and residues; and (5) the fourth good pulp returns to the transition tank 1 and is processed, and the residues are fed into a waste tank. The technology can reduce the residue discharge amount of the waste paper pulping fine screening section by 10-20% on the basis of ensuring the quality of the pulp.

The invention relates to a clean production technology for processing low-grade laterite-nickel ore by sodium carbonate alkali fusion. The invention takes laterite-nickel ore as a raw material, causes laterite-nickel ore and sodium carbonate to roast at high temperature, washes and filters the roasted material to leach valuable metal salts, such as water-soluble chromium, aluminum and the like generated in the laterite-nickel ore after reaction. High-temperature roasting damages the crystal lattice structure of the laterite-nickel ore so as to greatly improve the leaching rate of subsequent high-pressure acid leaching technical nickel and cobalt and improve the grade of Fe in acid leaching dregs; filtrate is prepared into chromium salt and aluminum salt by operations, such as evaporation, crystallization, separation and the like, so that the laterite-nickel ore product is diversified. The leaching rate of hexavalent chromium in the laterite-nickel ore is more than 90%, the leaching rate of trivalent aluminum is more than 65%, the leaching rate of nickel is more than 98%, the dipping rate of the chromium is more than 94%, and Fe content of fine iron powder in the acid leaching dregs is more than 61%.

The invention relates to the technical field of comprehensive utilization of phosphorite, in particular to a comprehensive utilization method of middle-low grade phosphorite. The method comprises the following steps: treating by adopting nitric acid, filtering, washing filter residues, removing calcium, adjusting the pH, concentrating and drying; the leaching efficiency of phosphorus element in the phosphorite is increased, acid in the residues is washed, and by virtue of calcium removal treatment, the removed calcium is converted by adopting an ammonium sulfate solution to obtain calcium carbonate, so that the slag discharging amount is reduced, the waste of sulfur element is avoided, and the phosphorite treatment cost is decreased; and by virtue of the subsequent neutralization of the calcium removing solution, the phosphorus is precipitated in a form of magnesium ammonium phosphate, nitrate radicals and phosphate radicals are separated, and the added value of products is increased.

The invention provides an electrochemical treatment method for arsenic-containing soot. The electrochemical treatment method comprises: (1) mixing an alkali and a solvent or mixing an alkali solutionand arsenic-containing soot to obtain a mixture; (2) placing the mixture as an electrolyte in an electrochemical reaction device, carrying out an electrochemical reaction, and introducing an oxidizinggas into the electrolyte during the electrochemical reaction; and (3) carrying out solid-liquid separation on the reaction product obtained in the step (2) to obtain the arsenic-containing solution.According to the present invention, the method has advantages of high extraction rate of arsenic, cleaning property, no pollution, mild process condition, low cost and low requirements on equipment; the impurity is not introduced so as to conveniently perform the subsequent separation; the concentration of the used alkali is low so as to reduce the alkali consumption; and the automation degree ishigh so as to reduce the manpower input, the good economic and social benefits can be provided, and the good application prospect can be provided.

The invention belongs to the technical field of grinding equipment and relates to a vertical grinding machine for glass fiber. The vertical grinding machine comprises a separator blanking pipe, a grinding roller, a separator rotor, a dust collecting pipe, an upper air ring, a lower air ring, a scraping plate, a dreg discharging hole, an air intake direction, a main speed reducer, an air intake valve, a feeding tank, a before-grinding belt scale, a material retaining ring and a manhole door; the vertical grinding machine is characterized in that the separator blanking pipe is vertically and downwards lengthened until the distance from the separator blanking pipe to the horizontal plane of a grinding disc is 250mm; the lengthened part of the separator blanking pipe is a cylindrical steel pipe of which the diameter is 426mm; the feeding tank extends inside the separator blanking pipe; the extension part of the feeding tank is hermetically connected with the part, in contact with the extension part of the feeding tank, of the separator blanking pipe; the height of the material retaining ring is increased by 140mm, and the clearance between each air ring and the material retaining ring is reduced to 30mm; a handle of the manhole door is additionally provided with a protective lock switch. The vertical grinding machine disclosed by the invention is reasonable, simple and convenient in structural design, low in cost, capable of improving the grinding efficiency and reducing the amount of discharged dregs, also capable of reducing abrasion, and capable of improving the safety as well during overhauling of equipment.