190 results about "Acid dissolution" patented technology

The invention provides a gold ore phase analysis method, and belongs to the field of mineral analys.The gold ore phase analysis method comprises the steps that a gold ore sample is prepared into ore pulp, the pH value is adjusted to 10-11, ultrasonic cavitation treatment is conducted after polyethylene glycol is added, and limonite turbid liquid and sedimentation bottom mud are obtained through separation; the turbid liquid is subjected to flocculation precipitation, drying, roasting, acid dissolution and impurity removal, and the limonite gold-loaded grade is obtained through the mass difference before and after dissolution and gold concentration determination; separating metal sulfide ore heavy minerals and gangue minerals from the settled bottom mud through artificial heavy elutriation, performing acid dissolution and impurity removal on the metal sulfide heavy minerals, and calculating the gold loading grade of the metal sulfide heavy minerals through mass difference and gold concentration determination; after gangue minerals are subjected to oxidizing roasting, the gold content is measured after concentrated acid dissolution; and calculating the distribution rate of gold based on the result. The gold loading grade and distribution of the limonite phase, the metal sulfide ore phase and the gangue mineral phase are measured in a split-phase mode, the method is highly matched with the gold ore development process, operation is easy and convenient, the result is reliable, and beneficiation and metallurgy technological process formulation and technical index pre-judgment can be effectively served.

The invention discloses a steel cylinder cleaning method. The method comprises the steps that ethyl alcohol is injected into a steel cylinder; rolling the steel cylinder filled with the ethanol for multiple times to rinse the inner wall of the steel cylinder, and then emptying the ethanol in the steel cylinder; injecting ultrapure water into the steel cylinder cleaned by the ethanol; rolling the steel cylinder filled with the ultrapure water for multiple times, rinsing the inner wall of the steel cylinder, and then emptying the ultrapure water in the steel cylinder; nitric acid is injected into the steel cylinder cleaned by the ultrapure water, metal ions in the steel cylinder are dissolved, and then the nitric acid in the steel cylinder is emptied; injecting ultrapure water into the steel cylinder to rinse the steel cylinder, and emptying the ultrapure water in the steel cylinder; taking the discharged ultrapure water as a sample, and detecting the content of residual metal ions in the steel cylinder; according to the obtained metal ion content, whether the steel cylinder meets the cleanliness requirement or not is judged, if the cleanliness requirement is met, a small amount of nitric acid is added into the steel cylinder, sampling detection is conducted after the steel cylinder is moistened and washed, and if the test result is consistent with the previous metal ion content, the steel cylinder is clean. According to the steel cylinder cleaning method, external source introduction is avoided while metal ion impurities in the steel cylinder are treated.

The invention belongs to the technical field of geological sample analysis and detection, and particularly discloses a method for measuring the amount of each element of lithium ore in a closed acid-soluble system, and the method comprises the following steps: pretreating the lithium ore; the pretreated lithium ore is weighed and put into a closed sample dissolving device, hydrofluoric acid and purified nitric acid are sequentially added, and the closed sample dissolving device is closed; carrying out heat preservation on the closed sample dissolving device twice to obtain a test solution; and measuring the test solution by using an inductively coupled plasma mass spectrometer to obtain a working curve, and calculating the content of the analysis element in the sample solution by using the working curve. The method for determining the amount of each element in the lithium ore by adopting the closed acid-soluble system has the characteristics of simplicity in operation, high efficiency and good stability, realizes simultaneous determination of the amount of lithium, rubidium, cesium, beryllium, strontium, niobium, tantalum, zirconium, hafnium and rare earth elements in the large-batch lithium ore, and further provides a reference for determination of main trace elements in the lithium ore.

The invention provides a method for recovering scandium from scandium-containing lithium slag and a pretreatment method of the scandium-containing lithium slag. The method for recovering scandium from the scandium-containing lithium slag comprises the following steps: mixing the scandium-containing lithium slag with concentrated sulfuric acid, and heating and roasting to obtain a roasted product; the roasted product is subjected to water leaching, and scandium-containing leaching liquid and leaching residues are obtained; the scandium-containing leachate is extracted, and a scandium-containing organic phase and raffinate are obtained; washing the scandium-containing organic phase to obtain a purified scandium-containing organic phase and a washing solution; carrying out reverse extraction on the purified scandium-containing organic phase, and filtering to obtain a reverse extract; the reverse extract is subjected to acid dissolution, and a scandium-containing acid solution is obtained; adding oxalic acid into the scandium-containing acid solution for precipitation, filtering to obtain scandium oxalate precipitation, and roasting to obtain scandium oxide.

The invention relates to a method for high-value utilization of waste lithium iron phosphate battery lithium extraction slag, and belongs to the technical field of waste lithium ion battery resource utilization. The method comprises the following steps: S1, mixing the lithium iron phosphate lithium extraction slag with a low-concentration sulfuric acid solution in proportion, carrying out countercurrent washing, carrying out solid-liquid separation, carrying out acid dissolution on a solid, carrying out gradient recycling on a washing solution, and carrying out resin adsorption and reverse osmosis treatment on a high-impurity washing solution for recycling; s2, reacting the pretreated solid with medium-concentration sulfuric acid, reducing a dissolved solution by using iron powder, then carrying out solid-liquid separation to obtain a first batch of ferrous sulfate heptahydrate, adding concentrated sulfuric acid into mother liquor, carrying out secondary crystallization, then carrying out solid-liquid separation, and recrystallizing the obtained solid by using washing wastewater to obtain a second batch of ferrous sulfate heptahydrate; s3, recovering sulfuric acid by adopting a membrane treatment method, and recovering phosphoric acid from residual mother liquor by adopting an extraction method; or directly treating the lithium iron phosphate waste residue. According to the method, efficient separation and recovery of iron and phosphorus resources and full-component high-value utilization of the lithium iron phosphate lithium extraction slag are realized.

The invention relates to the technical field of detection, and particularly provides a method for determining the quality and purity of silver in a silver-gold-plated product. The determination method comprises the following steps: dissolving a surface gold plating layer of a silver-plated product with aqua regia, and then dissolving a silver chloride protective film on the surface of silver with ammonia water, so that the problem that the mass of silver cannot be accurately weighed after the gold plating layer in the product is removed is solved, and the problem that the silver chloride protective film hinders the dissolution of pure silver with nitric acid to influence the determination is also solved. Thiourea is further adopted to dissolve a complex of diamine and silver, the situation that when silver is dissolved, added nitric acid reacts with the complex of diamine and silver to generate silver chloride precipitates is prevented, an ammonium nitrate solution is used for washing thiourea, a flame atomic absorption spectrometry method is adopted for conducting mass correction on silver in the solution obtained after aqua regia gold is dissolved, and the total silver mass is obtained through calculation. According to the determination method, the quality and the purity of the silver in the silver-plated product can be relatively accurately obtained.

This invention discloses a method for resolving isomers of methylfenacin ester, comprising: firstly, dissolving methylfenacin ester in a first solvent and adding L-tartaric acid, dissolving until clear; then adjusting the system temperature to 40℃-53℃ and adding L-tartaric acid seed crystals of the target isomer; subsequently, cooling the system to 20℃-30℃, filtering the precipitated product, and obtaining the L-tartaric acid seed crystals of the target isomer as the filter cake; dissociating the L-tartaric acid seed crystals of the target isomer using an alkaline resin, collecting the filtrate, and drying the filtrate to obtain the target isomer of methylfenacin ester. This invention achieves the resolution of isomers of methylfenacin ester by using L-tartaric acid, and through optimization of conditions, achieves a yield of not less than 74.1% and an ee of 91.1% for the target isomer of methylfenacin ester. The resolution method provided by this invention is simple to operate, easy to control, suitable for large-scale production, and meets industrial needs.

The invention relates to a method for measuring and analyzing nickel, silicon and phosphorus in nickel-containing pig iron, in particular to the technical field of detection and analys.The measuring and analyzing method comprises the steps that a nickel-containing pig iron sample is drilled, sampled and separated through a hard alloy drill bit, and a test sample is obtained; sequentially carrying out acid dissolution, solid-liquid separation and constant volume on the obtained test sample to obtain a test solution; measuring the contents of nickel, silicon and phosphorus in the obtained test solution by adopting a full-spectrum direct-reading inductively coupled plasma emission spectrum; a standard curve used in the full-spectrum direct-reading inductively coupled plasma emission spectrum measurement is obtained by dissolving a gradient nickel-containing pig iron standard sample to a constant volume. According to the determination and analysis method provided by the invention, the detection process is designed, so that the nickel, silicon and phosphorus elements in the nickel-containing pig iron with the nickel content of 8-15% can be jointly determined, and a scientific data basis is provided for production management and control.

Provided herein are compositions and methods for removing a coating, such as an environmental barrier coating (EBC), from a substrate. By some approaches, a method for removing a coating from a substrate comprises contacting the coating with a salt, the salt being a solid. The method also involves heating the coating and the salt to a temperature at or above the melting point of the salt to convert the coating to a dissolvable reaction product by fusion of the coating with the salt. After forming the dissolvable reaction product, the product is then dissolved using an acid to remove at least a portion of the coating from the substrate.

The application provides a method for recovering valuable metals in waste lithium battery black powder based on a eutectic solvent, uses a green solvent system composed of a choline / guanidine compound A containing a quaternary ammonium salt structure and an organic carboxylic acid compound B containing two or more carboxyl groups to recover valuable metals in waste lithium battery black powder, realizes preliminary and efficient separation of lithium cobalt manganese and nickel and graphite, recovers cobalt, manganese and lithium from the leaching solution through a step-by-step precipitation method after the lithium cobalt manganese enters the leaching solution, recovers nickel and graphite through acid dissolution separation of the mixture containing nickel and graphite, separates and recovers the mixture of nickel and graphite through subsequent treatment, the leaching conditions are mild, the pollution is small, the cost is low, and the method has good social and economic benefits; the method provided by the application can produce a plurality of high-value products, has the advantages of strong adjustability, high precipitation efficiency, green environmental protection and low cost, and has wide application value in the separation and recovery of valuable metals and graphite resources in battery black powder.

The invention discloses a method for stabilizing treatment of chromium-containing sludge and recovery of magnetic ferrochrome oxide, which adopts a simple solvothermal process, uses ethylene glycol as a reducing solvent, prevents Cr (III) from being oxidized into Cr (VI) in the solvothermal process, and converts iron-chromium hydroxide in the treated chromium-containing sludge into magnetic iron-chromium oxide, so that the magnetic ferrochrome oxide is recovered. The residual calcium-containing phase in the original chromium-containing sludge can be removed through an acid dissolution method, and finally the magnetic iron-chromium oxide with the calcium content lower than 2% is obtained. After treatment, the chromium content in the ethylene glycol solvent is lower than 0.2 mg / L, the next batch of sludge treatment can be carried out, and meanwhile, the chromium content in the acidic calcium ion leachate is lower than 0.9 mg / L. The method is simple in process, low in requirement on industrial equipment and low in required energy consumption, and meanwhile, the product obtained through treatment can show certain application potential in the fields of environmental protection, high-end manufacturing and the like.

This invention discloses a method for preparing hollow metal sulfides based on a mild template method using calcium carbonate. Calcium chloride powder and potassium carbonate powder are uniformly dispersed separately in an alcohol solution. The two solutions are then mixed and allowed to stand for aging to obtain solution A. Simultaneously, thioacetamide is dissolved in the alcohol solution to obtain solution B, and a chloride is dissolved in the alcohol solution to obtain solution C. The chloride is either stannous chloride or copper chloride. Then, solutions B and C are added sequentially to solution A at a molar ratio of thioacetamide to chloride of 2:1 and mixed uniformly to obtain solution D. Solution D is then placed in a polytetrafluoroethylene (PTFE) reactor and reacted at 140–180°C for 12 hours. Carbon dioxide is then continuously bubbled through the reactor for 2–3 hours. The mixture is filtered and washed with water and ethanol to obtain the hollow metal sulfides. This invention can obtain hollow metal sulfides with different morphologies and avoids the contamination problems associated with high-temperature calcination or acid dissolution for template removal.

The invention discloses an aluminum oxide proppant and a preparation process thereof, and belongs to the technical field of ceramic fillers. The aluminum oxide proppant is prepared from the following raw materials in parts by mass: 55-72 parts of bauxite; 15 to 25 parts of calcined kaolin; 5 to 10 parts of potassium feldspar; 0.3 to 0.9 part of manganese dioxide; 0.1 to 0.4 part of titanium dioxide; 4-8 parts of a reinforcing agent; the reinforcing agent is formed by mixing co-fired zirconium-based premixed powder and carbonate. The preparation method comprises the following steps: performing conventional wet-process ball-milling to form slurry, performing spray granulation, rolling and forming, performing segmented firing and granulating. According to the scheme, a stable secondary phase is generated in situ between aluminum oxide frameworks in the sintering process, stable zirconium dispersion distribution is achieved, densification and grain boundary stabilization are achieved with low addition amount, the breakage rate under the specified pressure grade is reduced, the acid dissolution rate under the mixed acid condition is reduced, and the product granularity and sphericity are stable.

The invention discloses an armored sand-ceramsite bimodal proppant based on performance matching as well as a preparation method and application thereof, and relates to the technical field of oil and gas exploitation. The proppant comprises ceramsite and armored sand which are compounded according to the mass ratio of (20: 80)-(60: 40), the volume density ratio of the ceramsite to the armored sand is 0.9-1.1, the median particle size ratio of the ceramsite to the armored sand is 1.5-3.0, it can be ensured that the proppant is evenly and stably conveyed to a target crack, the ceramsite forms a bearing framework, gaps are filled with the armored sand, and a synergistic and stable composite supporting structure is constructed. According to the proppant, the four-in-one performance matching design of volume density, breakage rate, acid solubility and particle size is adopted, the obtained proppant is superior to a conventional proppant in breakage resistance, acid corrosion resistance and long-term flow guide performance, the preparation cost is low, the defects of performance mismatch, system failure and the like of the conventional proppant can be overcome, and the proppant has wide application prospects in hydraulic fracturing construction of oil and gas fields.

The application discloses a method for recovering and purifying chloroiridic acid from an iridium-containing waste catalyst, which comprises the following steps: firstly, mixing the iridium-containing waste catalyst with a reaction aid and a solid oxide, and then performing a melting reaction under the temperature condition of 250-400 DEG C to obtain an iridium oxide melt which is hardly soluble in water; secondly, adding water to the melt to remove impurities, and then filtering to obtain the iridium oxide; finally, adding acid to the iridium oxide to obtain a chloroiridic acid solution. The method for recovering and purifying chloroiridic acid from the iridium-containing waste catalyst can obtain the iridium oxide which is only soluble in acid but hardly soluble in water after the melting reaction under the temperature condition of 250-400 DEG C, and then the metal impurities and the catalyst carrier in the catalyst can be removed by simple water washing, and the chloroiridic acid can be obtained by acid leaching, so that the method is short in route, low in cost, and suitable for industrial application; in addition, the purity of the chloroiridic acid is high (more than 99.95%), and the recovery rate is also high (more than 98%).

The invention relates to a process for preparing nylon 52 salt with low energy consumption, which comprises the following steps: dissolving oxalic acid in absolute ethyl alcohol to form an oxalic acid ethanol solution; the method comprises the following steps: slowly dripping pentamethylene diamine into an oxalic acid ethanol solution for reaction, and gradually separating out a nylon salt solid from the solution along with the proceeding of the reaction; and continuously stirring and fully reacting, carrying out solid-liquid separation by adopting a suction filtration mode, washing and drying to finally obtain a nylon salt solid. The process for preparing the nylon 52 salt is mild in reaction condition, especially can form salt at room temperature, and not only reduces energy consumption, but also can reduce by-product impurities possibly generated in high-temperature reaction due to the fact that high-temperature heating is avoided. Besides, inert gas protection is not needed in the whole salt forming process, the pH value of the reaction process does not need to be controlled, operation is easy and convenient to control, and the prepared nylon 52 salt has the advantages of being high in yield and purity.

The invention relates to a sample pretreatment method for chromite microelement analysis. The method comprises the following steps: firstly, treating a sample to specific particle size distribution (Dv (50) lt, 5 [mu] m, Dv (90) lt, 20 [mu] m) through physical accurate grinding, and then adopting an improved two-step acid dissolution and digestion process: firstly, destroying main crystal lattices of minerals by using mixed acid, then, carrying out targeted dissolution on a residual insoluble phase by using aqua regia, and finally, carrying out chlorine removal treatment to obtain a solution to be detected. Through the synergistic effect of physical accurate grinding and secondary acid dissolution, almost complete decomposition of chromite is achieved, especially the extraction efficiency of key indissolvable elements such as Sc and Zn is improved by 20% or above, the accuracy and precision of ICP-MS analysis results are remarkably improved, and the problem that microelement measured value systematicness is low due to incomplete dissolution in a traditional method is solved.

The utility model provides an acid dissolution experiment device, and relates to the technical field of experiment devices.The acid dissolution experiment device comprises at least two acid storage containers, a mixing container, at least two flow meters and at least two control valves, all the acid storage containers are arranged in parallel, the mixing container is provided with a mixing cavity, all the acid storage containers are communicated with the mixing cavity, and the flow meters are arranged in the mixing cavity; a flow meter is arranged on a communication path of each acid storage container and the mixing container, and a control valve is arranged on a communication path of each flow meter and the mixing container; according to the acid dissolution experiment device, the at least two acid storage containers and the flow meters and the control valves which are in one-to-one correspondence with the acid storage containers are arranged, so that the instantaneous flow rate and the total flow rate of the acid solution flowing into the mixing container from the acid storage containers can be controlled, and the technical problem of difficulty in simultaneously and quantitatively adding multiple acids in the acid dissolution experiment device is solved; the requirements of experiments on the acid solution are met, and the accuracy and reliability of experimental data are improved.

The invention provides a ternary iron-lithium fully-compatible integrated circulation treatment method and system application, and the method comprises the following steps: mixing lithium iron phosphate black powder and ternary material black powder, carrying out first acid leaching, carrying out primary copper removal on a first acid leaching solution, carrying out a mixed reaction on a copper-removed solution, an oxidizing agent and a crystal inhibition dispersant, and carrying out secondary acid leaching on a second acid leaching solution; first ferrophosphorus slag and dephosphorized liquid are obtained; the crystal inhibition dispersing agent comprises an organic phosphonic acid compound; performing iron and aluminum precipitation on the phosphorus-removed liquid to obtain iron and aluminum slag and iron and aluminum-removed liquid; the first ferrophosphorus slag and the iron-aluminum slag are subjected to alkali dissolution, second ferrophosphorus slag and aluminum-containing liquid are obtained, the second ferrophosphorus slag is subjected to acid dissolution, and ferrophosphorus liquid is obtained; and performing secondary copper removal on the iron and aluminum removed liquid to obtain a pre-extraction liquid and copper slag, and extracting the pre-extraction liquid to obtain a nickel salt solution, a cobalt salt solution and a lithium salt solution. Various wastes such as battery powder, pole piece powder, slurry and the like of the ternary lithium battery and the lithium iron phosphate battery can be fully compatible and integrally recycled.

The invention discloses a heavy metal emission reduction and sludge reduction treatment process method for circuit board wastewater. The invention provides a layered precipitation strategy of'first acid, second alkali and second sulfur '. The method comprises the following steps: performing acid precipitation on alkaline organic wastewater by using acidic wastewater, and recovering printing ink residues; carrying out air stripping treatment on the copper ammonia wastewater by utilizing an alkaline condition, and precipitating high-purity copper hydroxide; and finally, carrying out deep precipitation on residual complexing heavy metals by utilizing excessive sulfides in the pretreatment stage, and further recovering copper resources in the comprehensive water tank through coprecipitation of copper hydroxide and copper sulfide. Sludge generated in each process is classified and treated; printing ink slag, biochemical residual sludge and copper / nickel sulfide sludge are subjected to synergistic pyrogenic process treatment; copper hydroxide sludge is selectively subjected to acid dissolution to prepare copper sulfate. Lime, ferrous sulfate and polyaluminum are not used in the whole process. According to the method, the medicament is utilized to the maximum extent, the sludge is reduced by 50% or above, and the resource value of valuable metal is increased by 3-5 times.

The invention discloses a rare earth radioactive slag reduction and barium sulfate slag recycling method based on transformation and decomposition of barium sulfate. The method comprises the following steps: drying, ball-milling and screening rare earth radioactive slag, adding water into sodium hydroxide, and mixing to obtain rare earth slag; roasting and transforming the rare earth slag under the condition of introducing carbon dioxide; washing the roasted and transformed rare earth slag with water; the washed rare earth slag is subjected to acid dissolution and solid-liquid separation, and high-silicon slag without radioactive elements and an acid solution with the radioactive elements are obtained; sulfuric acid is added into the acid solution step by step for fractional precipitation and radium removal, and barium and radium residues containing radioactive elements and barium sulfate residues without radioactivity are obtained through solid-liquid separation; adjusting the mass ratio of the barium sulfate slag and sodium hydroxide, then carrying out alkali conversion and acid dissolution to obtain a barium chloride solution, and recycling the barium chloride solution for removing sulfate radicals from the rare earth feed liquid. According to the method, barium sulfate in the rare earth radioactive slag can be transformed into more than 95% of soluble barium salt, the amount of the rare earth radioactive slag is reduced by more than 85%, and the barium circulation rate reaches more than 90%.

The application discloses a method for determining the gold-carrying amount of brown iron ore in heavy floatation tailings, which comprises the following steps: mixing the tailing sample with a composite reducing agent composed of flour, activated carbon, anhydrous sodium carbonate and ammonium sulfate; performing closed reduction roasting by subsection heating, constructing a loose porous structure and converting the gangue phase by the pore-forming effect of the ammonium sulfate and the fluxing modification of the sodium carbonate; obtaining the magnetic product by grinding and ultrasonic-assisted magnetic separation, and then performing oxidation roasting and acid dissolution treatment, removing the modified gangue by mass difference subtraction, calculating the net mass of the brown iron ore, and combining with the liquid phase gold content determination to obtain the gold-carrying amount; and the application effectively solves the problems of serious micro-fine particle brown iron ore wrapping, easy roasting and large gangue interference, and realizes the accurate determination of the gold-carrying amount.

The invention relates to the technical field of mineral content detection, in particular to a method for simultaneously determining total barium and sulfur in barite through acid dissolution-inductively coupled plasma emission spectrometry. The method comprises the following steps: adding nitric acid and hydrochloric acid into barite, heating on an electric heating plate, adding a chromium internal standard solution and a nitric acid solution, heating, cooling, and determining by using an inductively coupled plasma emission spectrometer. According to the method, simultaneous determination is achieved in an acid dissolution mode, the detection efficiency is improved, time and cost are saved, the whole test solution preparation process is relatively simple, accurate volume determination is not needed, sample digestion treatment can be completed through common means such as electric hot plate heating under conventional laboratory conditions, and the method is more stable, easy and convenient to operate, easy to master and suitable for large-scale popularization and application. The reproducibility is good, and popularization and application are convenient. Meanwhile, the method can improve the accuracy and precision of a measurement result, so that the measurement result is more reliable.

The application discloses a method for continuously preparing 4-chlorobenzenesulfonyl chloride, and the 4-chlorobenzenesulfonyl chloride is prepared through a continuous equipment, and the specific steps are as follows: step one, 4-chlorobenzenesulfonic acid is dissolved in halogenated hydrocarbon to prepare a 4-chlorobenzenesulfonic acid solution for standby; step two, the 4-chlorobenzenesulfonic acid solution and chlorosulfonic acid with a mass concentration of 99% are mixed in a mixing pump; step three, the 4-chlorobenzenesulfonyl chloride is prepared through temperature control and stirring reaction of the mixed solution in an n-stage continuous reaction equipment. The application has the following beneficial effects: through directional selection of halogenated hydrocarbon as chloroform, and through the continuous reaction device, the conversion rate of chlorosulfonic acid in the application reaches more than 92% compared with the selection of other halogenated hydrocarbons, and the molar yield of the 4-chlorobenzenesulfonyl chloride product can reach more than 82%.

This invention discloses a method for the resource recovery of battery powder, belonging to the field of resource recycling technology. The method includes the following steps: adding a phosphorus-containing mixed acid solution and hydrogen peroxide to the battery powder for acid dissolution, filtering to obtain a metal leachate; adding a first pH adjuster to the metal leachate to adjust the pH to 1.5–2.7, filtering to obtain an iron-removed leachate and crude iron phosphate; adding a second pH adjuster to the iron-removed leachate to adjust the pH to 3.5–5.5, filtering to obtain a qualified leachate and hazardous iron-aluminum slag; mixing the hazardous iron-aluminum slag with a reducing agent, and then carrying out a solid-phase oxidation reaction under heating conditions to obtain a precursor; washing the precursor with hot water, filtering to obtain a metal sulfate solution and directly discardable iron-aluminum oxide slag; the method described has high recycling efficiency and can convert hazardous solid waste into general solid waste.

This invention relates to the field of oil and gas drilling technology, specifically disclosing a surface-modified acid-soluble weighting agent, its preparation method, and its application. The surface-modified acid-soluble weighting agent comprises 80-99 wt% hydroxyapatite and 0.5-3 wt% surface modifier, and has a density of 2.9-3.2 g / cm³. 3 The surface-modified acid-soluble weighting agent of this invention can increase the weight of drilling fluid to 1.7 g / cm³, provided that the acid solubility is ≥80%. 3 It can still maintain good rheological properties, filtration loss, and settling stability, thus achieving the goal of simultaneously ensuring good drilling fluid rheological properties, filtration loss, settling stability, and acid dissolution and plugging effect.

This invention relates to the field of lithium extraction technology from lithium-containing organic wastewater, specifically to a method for preparing battery-grade lithium carbonate from lithium-containing organic wastewater. The method provided by this invention first recovers organic acids from the wastewater through esterification and hydrolysis reactions. Then, under pH 11-12 conditions, lithium is precipitated with trisodium phosphate to obtain crude lithium phosphate solid. The lithium is then enriched, dissolved in acid, and extracted to remove phosphoric acid. The raffinate is adjusted to pH 9-11 to remove impurities, yielding a lithium sulfate solution. After concentration using MVR (Medium-Volume Reduction), impurities are further removed under pH 10.5-11.5 and activated carbon adsorption conditions to obtain a pure lithium sulfate solution. The obtained pure lithium sulfate solution is mixed with a carbonate solution to obtain crude lithium carbonate. Finally, after washing, drying, crushing, and iron removal, battery-grade lithium carbonate is obtained.

A preparation method of a digestion solution for corrosion of tantalum-niobium-containing alloy waste comprises the following synthesis steps: taking a certain amount of halogenated iron salt, adding the halogenated iron salt into dilute halogen acid under high-speed stirring until the halogenated iron salt is completely dissolved, then adding hexafluorotitanic acid and titanyl sulfate solids according to a certain proportion to be completely dissolved, then adding excessive newly-prepared titanium hydroxide to react for a period of time, and finally adding a catalyst to react for a period of time; and filtering and adding graphite powder for later use. The decomposition method comprises the following steps: shearing and crushing the tantalum-niobium alloy-containing waste material to obtain the result; and adding the digestion solution into a small section with the diameter of 50 mm, heating to 40-70 DEG C, dropwise adding hydrogen peroxide, cooling the discharged gas, and enabling the condensed water to flow back to the system. Filtering after sampling and detecting that no metal exists, adjusting the filtrate to an initial state after analyzing components, adding a proper amount of sulfuric acid and hydrofluoric acid into a filter cake to adjust and dissolve until the filter cake meets the extraction requirement, and entering an extraction process line.

This invention provides a method for preparing high-purity alumina using kaolin. The method comprises the following steps: S1: Pre-treating kaolin to obtain pre-treated kaolin; S2: Adding hydrochloric acid solution to the pre-treated kaolin for acid purification, followed by activation to obtain activated kaolin; S3: Adding hydrochloric acid solution to the activated kaolin for acid dissolution, followed by concentration and sedimentation to obtain crude aluminum chloride solution and silica filter cake; S4: Purifying the crude aluminum chloride solution to obtain a high-purity aluminum chloride solution; S5: Preparing high-purity alumina using the high-purity aluminum chloride solution. This invention can reduce the production cost of high-purity alumina, and the obtained high-purity alumina has a purity ≥99.9%, which is beneficial for expanding the industrial application of high-purity alumina.

The application belongs to the technical field of wet assay, and provides a multi-module cooperative wet assay acid-dissolution automation device and method. The wet assay acid-dissolution automation device integrates a positive aqua regia real-time preparation pump group, a negative aqua regia real-time preparation pump group, a drop horizontal movement module and a cover opening module. The aqua regia real-time preparation, automatic cover opening, quantitative liquid addition and dynamic shaking are integrated in a single device, thereby solving the process fragmentation and cooperation failure caused by the traditional manual + multiple single machine mode.