155 results about "Tetrachloride" patented technology

The invention discloses a gas-sensitive material for monitoring an environment-friendly gas characteristic substance CO as well as a preparation method and application thereof, and relates to the technical field of gas-sensitive materials. The preparation method comprises the following steps: dissolving tin tetrachloride pentahydrate, sodium hydroxide and polyvinylpyrrolidone, adding ammonium fluoride, reacting at 155-165 DEG C, drying the product, and calcining at 295-305 DEG C to obtain SnO2 nanoparticles; the preparation method comprises the following steps: performing ultrasonic mixing on SnO2 deionized water dispersion liquid and MoS2 nanosheet ethylene glycol dispersion liquid, and then drying to obtain the MoS2 / SnO2 composite material with a mesoporous hollow nanotube structure, and the volume ratio of ethylene glycol to deionized water is (0.9-1.1): 1. The MoS2 / SnO2 gas sensitive material has the advantages of low density, high pore volume, large specific surface area, high structural stability and the like. And when applied to a CO resistive sensor, the catalyst has good CO selectivity, high sensitivity and good long-term stability.

The invention relates to a novel preparation method of tetra (dimethylamino) tin. The method comprises the following steps: in a nitrogen atmosphere, pumping an n-hexane solution of n-butyllithium and an n-hexane solution of dimethylamine into a pipeline through a propeller, mixing through a T-shaped joint, and reacting through a flow reactor 1 and a flow reactor 2 to obtain a lithium dimethylamide mixed solution; the method comprises the following steps: pumping a lithium dimethylamino mixed solution and a n-hexane solution of tin tetrachloride into a pipeline through a propeller, mixing through a T-shaped joint, and reacting through a flow reactor 3 and a flow reactor 4 to obtain a crude tetra (dimethylamino) tin product; and centrifuging and filtering the tetra (dimethylamino) tin crude product, adsorbing impurities by adopting a resin column, and carrying out reduced pressure distillation to remove the solvent, thereby obtaining the tetra (dimethylamino) tin. The adsorption resin column adopts modified macroporous adsorption resin, and is obtained by reacting, filtering and drying D190 macroporous styrene sulfydryl resin, dichloroethane, tetramethylguanidine, 5-allylpyrimidine-4, 6-diol and an ethylene boric anhydride pyridine complex.

The invention belongs to the technical field of new energy, and particularly discloses a catalyst for catalyzing conversion of glucose into 5-hydroxymethylfurfural and a preparation method of the catalyst. The method is used for solving the problem of low HMF selectivity in the process of converting glucose into HMF. The preparation method comprises the following steps: firstly, synthesizing hollow mesoporous silicon spheres in the presence of absolute ethyl alcohol by taking hexadecyl trimethyl ammonium bromide as a structure-directing agent, ammonia water for providing an alkaline environment and tetraethyl orthosilicate as a silicon source of silicon dioxide; then, filling sucrose serving as a carbon source into the hollow meso-porous silicon spheres, and carbonizing and removing silicon to obtain meso-porous carbon microspheres; and finally, dipping the mesoporous carbon microspheres in a tin tetrachloride pentahydrate solution to prepare the tin-loaded mesoporous carbon microsphere catalyst. The catalyst has a large specific surface area, an excellent pore structure and good hydrothermal stability, has two acidic sites of Lewis acid and # imgabs0 # acid at the same time, and can efficiently catalyze conversion of glucose into HMF.

The invention relates to the technical field of preparation of germanium dioxide, in particular to a preparation method of ultra-pure germanium dioxide, which comprises the following steps: grinding a germanium ingot to obtain germanium powder; transferring the germanium powder into a closed reactor, introducing high-purity chlorine into the closed reactor, and fully reacting to obtain germanium tetrachloride; distilling and purifying germanium tetrachloride; adding ultrapure water into the purified germanium tetrachloride, fully stirring, standing, and filtering to obtain germanium dioxide precipitate; and cleaning, drying and calcining the germanium dioxide precipitate to obtain the ultra-high-purity germanium dioxide with the purity of 7N or above. Germanium dioxide obtained by the preparation method of ultra-pure germanium dioxide is high in purity and high in yield, the chlorine content is lower than 0.003%, and the preparation requirements of BGO crystals are met.

The invention relates to a preparation method of a pectin-derived carbon-coated amorphous tin-zinc composite oxide lithium ion battery negative electrode material. The method comprises the following steps: dropwise adding a tin tetrachloride solution and an acidified zinc oxide solution into a pectin solution to obtain a metal ion-pectin dispersion liquid; adding ammonia water to obtain a pectin precursor solution; freezing and solidifying with liquid nitrogen; and after freeze-drying, roasting for 3-5 hours to obtain the pectin derived carbon coated amorphous tin-zinc composite oxide lithium ion battery negative electrode material. The reversible specific capacity of the obtained composite material reaches 1339 mA h g <-1 > after 100 cycles under the current density of 0.2 A g <-1 >.

This application relates to the field of metal surface treatment materials, specifically disclosing a silicon-integrated inorganic supercrystalline thermal energy powder and its preparation and application methods. The silicon-integrated inorganic supercrystalline thermal energy powder comprises raw material A and raw material B. Raw material A includes the following: magnesium oxide, sodium fluoroaluminate, sodium polyphosphate, zinc oxide, crystalline tin tetrachloride, silicon dioxide, and boric acid. Raw material B includes the following raw materials in parts by weight: spodumene, lithium carbonate, titanium dioxide, zinc silicate, sodium carbonate, antimony trioxide, albite, fluorite, boric acid, sodium hydroxide, and yttrium oxide. The inorganic supercrystalline thermal energy powder of this application has advantages such as corrosion resistance and oxidation resistance, good thermal stability, no damage from thermal cycling, high hardness, wear resistance and high temperature resistance, energy saving, water scale reduction, and the ability to replace organosilicon high-temperature resistant special coatings, baking paints, enamel paints, and ceramic floor glazes.

The present invention discloses a method for separating nickel and iron from a nickel-iron alloy by chlorination roasting: (1) placing the nickel-iron alloy in a roasting furnace; (2) introducing a gaseous chlorinating agent into the roasting furnace for staged roasting to obtain roasting slag and a roasting gas phase; wherein the gaseous chlorinating agent is a mixture of chlorine and gaseous ferric chloride; and (3) condensing the roasting gas phase obtained in step (2) in stages to obtain solid ferric chloride and liquid silicon tetrachloride, respectively. The present invention controls the composition of the chlorinating agent during the chlorination roasting process to achieve selective and directional volatilization of iron into the gas phase while preventing nickel from being chlorinated. Thus, nickel and iron in the nickel-iron alloy can be separated in a single step, and the process flow is short.

This invention discloses a method for preparing a high-temperature resistant, strongly basic anion exchange resin, belonging to the field of ion exchange resins. The method includes three steps: First, white spheres with a crosslinking degree of 6-10 undergo a chloromethylation reaction by sequentially adding zinc dichloride and tin tetrachloride to improve the uniformity of the chloromethyl group distribution in the chlorospheres; second, the chlorospheres undergo an etherification reaction using tetrabutylammonium bromide as a phase transfer catalyst, and the dropping rate of sodium methoxide solution is controlled to improve the etherification conversion rate; finally, the etherification product undergoes a quaternization reaction with a trimethylamine aqueous solution to obtain the strongly basic anion exchange resin. This invention, by selecting the degree of crosslinking and optimizing the catalyst addition method for chloromethylation and the sodium methoxide dropping rate for the etherification reaction, results in a more uniform distribution of quaternary ammonium groups in the resin, significantly improving the ion exchange capacity and high-temperature resistance of the resin.

The invention discloses a negative electrode electrolyte and an acidic tin-bromine flow battery, and belongs to the technical field of energy storage. The negative electrode electrolyte provided by the invention comprises an active substance and a supporting electrolyte, the active substance comprises tetravalent tin salt; the tetravalent tin salt is selected from at least one of tin tetrachloride, tin sulfate, tin bromide and stannate; the supporting electrolyte is selected from at least one of sulfuric acid, hydrochloric acid, perchloric acid, methanesulfonic acid, hydrobromic acid and hydriodic acid. According to the acidic tin-bromine flow battery provided by the invention, a proper tin ion ligand is selected in the negative electrode electrolyte, and the formed tin-based complex can effectively improve the redox kinetics of Sn < 4 + > / Sn < 2 + > and improve the efficiency of the tin-bromine flow battery. Besides, the modification of the negative electrode can further improve the adsorption of reactive active substances and improve the electron transfer rate, and the high specific surface area can provide more active sites, so that the reaction polarization is reduced and the battery performance is improved.

The invention discloses a large-area continuous MOF membrane and a preparation method and application thereof.The preparation method comprises the following steps that S1, zirconium tetrachloride and 1, 3, 5-tris (4-carboxyphenyl) benzene are dissolved in N, N-dimethylformamide, then formic acid and water are added, the obtained mixed solution is sealed and then placed in a drying oven for heat preservation, then a sulfonating reagent is added, standing is conducted after backflow is conducted for a period of time, and a sulfonating agent is obtained; centrifugally washing with ultrapure water to obtain a uniform dispersion liquid; s2, a substrate is washed in ethyl alcohol and deionized water for standby application; s3, fixing a substrate on a blade coater, blade-coating and tiling the prepared dispersion liquid on the surface of the substrate, and drying to obtain an MOF film; and S4, transferring the MOF film into a vacuum oven to further stabilize the structure. The two-dimensional MOF nanosheet can be conveniently and rapidly prepared by using a solvothermal method, a large-area continuous MOF membrane can be rapidly prepared by self-assembly through a blade coating method, and excellent lithium ion selectivity and permeability are shown under dual regulation and control of a size effect and an affinity effect of a sulfonic acid group.

The invention discloses continuous synthesis equipment for high-purity tetrachloroethylene. The continuous synthesis equipment comprises a chlorination synthesis device, an energy-saving device, a cooling and washing device, a carbon tetrachloride refining device and a tetrachloroethylene refining device. The invention further discloses a continuous synthesis process of the high-purity tetrachloroethylene. The continuous synthesis process comprises the steps of chlorination synthesis, cooling and washing, carbon tetrachloride refining and tetrachloroethylene refining. The reaction in the tube nest of the chlorination reaction kettle generates carbon tetrachloride, the carbon tetrachloride in the shell pass reacts to generate tetrachloroethylene, and the heat released by the first-step reaction promotes the forward proceeding of the second-step reaction. The heat-conducting oil is used for removing heat after reaction and supplying the heat to the rectification system, so that the energy consumption of the system is reduced. According to the invention, the carbon tetrachloride crude product is refined and then returns to the system, the tetrachloroethylene yield is high, and the conversion rate of tetrachloroethylene in the synthesis kettle is not influenced. The heat transfer oil is used for heating the rectification system and a tetrachloroethylene high-low pressure rectification mode, and the energy of the system is saved by more than 50%.

The application relates to the technical field of metal organic thin layer material preparation, in particular to a kilogram-level preparation method of metal organic thin layer material. The preparation method comprises the following steps: S1, adding zirconium tetrachloride and H2BPYDC into a polytetrafluoroethylene reaction kettle, dissolving the zirconium tetrachloride and the H2BPYDC, and then adding a composite; S2, sequentially adding a DMF solution of palladium fluoroacetate, a catalyst and concentrated hydrochloric acid into the reaction kettle; S3, transferring the reaction kettle into an oven, centrifuging to obtain a cyan suspension after 18-20 hours, dispersing the cyan suspension in a DMF solution in batches at 60 DEG C, placing for 5-6 hours, removing unreacted substrates, and obtaining a solid; S4, cleaning the solid obtained in S3 by using DMF and tetrahydrofuran respectively, and vacuum drying for 12 hours to obtain the metal organic thin layer material. The kilogram-level preparation method of metal organic thin layer material is provided, so as to solve the problems of low preparation yield, slow rate and difficulty in kilogram-level preparation of metal organic thin layer material in the related art.

A method and application of CO2 laser-induced synthesis of jujube-shaped heterostructure electrocatalysts, after mixing a sulfur source and distilled water, adding a cobalt source, sodium citrate and a tin source, stirring evenly, the sulfur source is L-cysteine, ammonium thiocyanate, thiourea or sulfur powder, the cobalt source is hexahydrated cobalt nitrate, cobalt chloride and cobalt acetylacetonate, the tin source is stannous chloride, tin tetrachloride or stannous sulfate, hydrothermally reacting in a stainless steel autoclave, washing, centrifuging, vacuum drying at room temperature, obtaining an electrocatalyst precursor; grinding the electrocatalyst precursor into powder, evenly paving, and inducing CO2 laser in an air atmosphere; cooling to room temperature, washing, drying and grinding into powder to obtain a jujube-shaped heterostructure CoS / SnO2@C electrocatalyst. Advantages: simple synthesis, short time consumption, low energy consumption, good dispersibility, excellent ORR and OER electrocatalytic performance, can be used to prepare cathode electrocatalysts for lithium oxygen batteries.

The invention discloses an air cathode Sn-CoSb / NC of a zinc-air battery and a preparation method of the air cathode Sn-CoSb / NC. The preparation method comprises the following steps: preparing a cobalt-doped ZIF-8 (Co-ZIF-8) precursor: mixing a methanol solution of dimethylimidazole with a methanol solution of zinc nitrate hexahydrate and cobalt nitrate hexahydrate, stirring at room temperature for 24 hours, centrifuging, washing and drying to obtain the Co-ZIF-8 precursor; the preparation method comprises the following steps: taking a small amount of N, N-dimethylformamide (DMF), adding tin tetrachloride pentahydrate and antimony trichloride, and stirring until the tin tetrachloride pentahydrate and the antimony trichloride are completely dissolved; then adding Co-ZIF-8 powder into the solution, stirring for 5 hours at room temperature, and then centrifuging and drying to obtain purple powder; and placing the powder in a tubular furnace, and carrying out high-temperature pyrolysis in an inert atmosphere to obtain the Sn-CoSb / NC electrocatalyst. The novel catalyst has excellent ORR functional activity, and as an air cathode of a zinc-air battery, high power density and excellent charge-discharge cycle stability are realized.

The invention relates to the field of electrocatalysts, in particular to a Ru t-ZrO2 / C electrocatalyst and a preparation method thereof.The preparation method includes the steps that zirconium tetrachloride, terephthalic acid, N, N-dimethylformamide and formic acid are put into a polytetrafluoroethylene lining to be subjected to a solvothermal reaction, and after the temperature is cooled to the room temperature, centrifugal washing and vacuum drying are conducted through DMF and methyl alcohol to obtain UiO-66 powder; secondly, dispersing the UiO-66 powder in methanol, adding ruthenium trichloride, stirring, centrifugally washing with methanol, and drying in vacuum to obtain a precursor Ru-UiO-66; and finally, sintering the precursor Ru (at) UiO-66 in a tubular furnace under an argon condition to obtain the Ru (at) t-ZrO2 / C electrocatalyst. According to the present invention, the strong interaction between the Zr-Ru bimetallic sites is combined with the strong conductive structure formed by ZrO2 and the carbon substrate, such that the prepared electrocatalyst has characteristics of low loading amount of the noble metal Ru cluster, excellent structure stability, high active site utilization rate, and efficient electron transfer with the MOFs carrier so as to show the efficient acid-base system electrocatalytic property;

A method for cleaning surfaces of a substrate processing chamber includes a) supplying a first gas selected from a group consisting of silicon tetrachloride (SiCl4), carbon tetrachloride (CCl4), a hydrocarbon (CxHy where x and y are integers) and molecular chlorine (Cl2), boron trichloride (BCl3), and thionyl chloride (SOCl2); b) striking plasma in the substrate processing chamber to etch the surfaces of the substrate processing chamber; c) extinguishing the plasma and evacuating the substrate processing chamber; d) supplying a second gas including fluorine species; e) striking plasma in the substrate processing chamber to etch the surfaces of the substrate processing chamber; and f) extinguishing the plasma and evacuating the substrate processing chamber.

The present invention discloses a production process of zirconium oxychloride and zirconium oxychloride. The process comprises the following steps: 1) Using zirconium tetrachloride as a raw material, preparing a first zirconium oxychloride solution; 2) Using high-purity zirconium oxychloride as a raw material, preparing a second zirconium oxychloride solution; 3) Simultaneously starting natural cooling for the first zirconium oxychloride solution and the second zirconium oxychloride solution. After the second zirconium oxychloride solution starts to crystallize, adding a preset mass of the second zirconium oxychloride solution to the first zirconium oxychloride solution to obtain a mixed solution; 4) Naturally cooling the mixed solution, and after crystallization, obtaining zirconium oxychloride crystals. The process of the present invention starts from a zirconium oxychloride solution, controls the crystallization process, reduces the impurity content in zirconium oxychloride, and improves the quality of zirconium oxychloride. The zirconium oxychloride of the present invention controls the crystallization process during crystallization, obtains crystals with higher purity, reduces the number of crystallization times, thereby achieving the improvement of the quality of zirconium oxychloride products and indirectly reducing the production cost of enterprises.

The invention belongs to the technical field of sponge zirconium reduction, particularly relates to a sponge zirconium reduction and evaporation integrated device and a sponge zirconium reduction and evaporation integrated method, and aims to solve the problems that zirconium tetrachloride needs to be mixed with magnesium to react during magnesiothermic reduction, and the existing mixing efficiency is low, so that the production efficiency is low and the energy consumption is increased. A reduction module is arranged above the tool bottom plate and comprises a tool mounting frame, a heating frame body is mounted on the tool mounting frame, a reduction furnace body is fixedly connected to the interior of the heating frame body, and a reduction furnace sealing cover plate is connected to an opening of the reduction furnace body through a bolt; and a mounting round hole is formed in the reduction furnace sealing cover plate. The sponge zirconium reduction and evaporation integrated device and method disclosed by the invention have the effects that zirconium tetrachloride and magnesium liquid are mixed more quickly and uniformly, so that the reduction reaction effect is improved, the production efficiency is improved, and meanwhile, the energy consumption is reduced.

Based on the characteristic that tin tetrachloride is easy to hydrolyze, efficient extraction of tin in the tellurium-deposited liquid is achieved through a two-step method of neutralization impurity removal and hydrolysis tin deposition, the pH value is adjusted firstly, stirring impurity removal is conducted, then heating hydrolysis tin deposition is conducted, the direct recovery rate of tin is 95% or above, the tin content of a product is also as high as 40% or above, and the method is suitable for industrial production. The lead content is lower than 0.5%, the chlorine content is lower than 2%, compared with an existing conventional neutralization precipitation method, the alkali liquor used in the method is little, and the impurity rate in the obtained tin material is low.

Tin tetrachloride pentahydrate, zinc nitrate hexahydrate and dimethylimidazole are used as raw materials, methanol is used as a solvent, and the tin-zinc bimetallic oxide, which is named Sn-Zn-O for short, is obtained through stirring, centrifugal drying and calcining; the material is an n-type semiconductor, and the chemical composition of the material is SnO2 and ZnO. The microstructure of Sn-Zn-O is a nano microsphere, and the particle size range of the Sn-Zn-O is 100-250 nm. The invention relates to a preparation method of a hydrogen sensor based on Sn-Zn-O, namely when the Sn-Zn-O is used as the hydrogen sensor, the optimal working temperature is 180 DEG C, the response value is 112 when the hydrogen concentration is 1000 ppm, the response time is 1.29 s, and the recovery time is 147 s. When the hydrogen concentration range is 0.1-2000ppm, the hydrogen sensor has different responses to hydrogen with different concentrations, and the lowest hydrogen concentration is detected to be 0.1 ppm.

The application discloses a kind of photocatalyst and preparation method thereof, the photocatalyst is flower ball layer structure, composition includes SnS2, SnS, the molar ratio of SnS2 With SnS is 1-2.5:1.The preparation method of the photocatalyst, including the following steps: (1) tin tetrachloride pentahydrate, sulfur source is placed in first liquid, carries out first hydrothermal reaction, obtains SnS2;(2) to SnS2 Adding stannous chloride dihydrate and sulfur source, carries out second hydrothermal reaction, washes, obtains SnS2@SnS photocatalyst and dries.This application provides photocatalyst, can achieve the effect of excellent reduction performance.

The application provides a preparation method of high-purity sponge zirconium and relates to the field of sponge zirconium preparation. The preparation method comprises the following steps: zircon sand is mixed with coke, petroleum coke, needle coke and pitch coke respectively, and then is loaded into a chlorination furnace in a layered manner from bottom to top; high-temperature chlorine gas is introduced into the bottom of the chlorination furnace to perform a chlorination reaction, so that first crude zirconium tetrachloride gas is obtained; a reduced nickel-based catalyst is added into each loading layer of the chlorination furnace; first cooling is performed to obtain crude zirconium tetrachloride solid, first heating is performed to obtain second crude zirconium tetrachloride gas, purification is performed to obtain refined zirconium tetrachloride gas, and second cooling is performed to obtain refined zirconium tetrachloride solid; second heating is performed on the refined zirconium tetrachloride solid to obtain high-purity zirconium tetrachloride gas; the high-purity zirconium tetrachloride gas is introduced into a reduction furnace containing molten magnesium metal to perform a reduction reaction, so that a mixed product is obtained; and the mixed product is subjected to reduced-pressure distillation to obtain the high-purity sponge zirconium. The preparation method provided in the application has high purity of the obtained sponge zirconium.

A gas detection fuse comprising a thin strip or sheet of a conductive material, such as a metal, connecting two electrodes for detecting a gas of interest. The metal is selected to be reactive with the gas of interest, and has a relatively large surface area, such that when the gas of interest contacts the metal, the electrical connection between the electrodes is broken (e.g., due to the metal losing physical integrity, or becoming non-conductive, as a result of the reaction with the gas). The gas of interest may be chlorine, and the conducting material may be tin. When the tin is exposed to chlorine the tin becomes oxidized to produce liquid tin tetrachloride, thus breaking the electrical connection.

The invention relates to a process for preparing a star copolymer of 1,3-diene and ethylene, the copolymer containing more than 50 mole percent ethylene units. The process comprises the polymerization of a monomeric mixture of 1,3-diene and ethylene in the presence of a catalytic system based on at least one neodymocene borohydride metallocene and an organomagnesium cocatalyst, followed by the reaction of tin tetrachloride with the polymerization reaction product, and then a chain-terminating reaction. The invention also relates to a star copolymer obtainable by the process according to the invention.

The present invention discloses a solvothermal method for synthesizing SnO2 nanoparticles in one step. The method comprises adding acetylacetone to isopropyl alcohol as a mixed solvent, adding tin tetrachloride, stirring thoroughly, reacting in a reactor at 180-220°C for 12-24 hours, naturally cooling, separating, washing, and drying to obtain SnO2 nanoparticles. The preparation method of the present invention has the advantages of mild reaction conditions and a simple and easy method. The SnO2 nanoparticles synthesized by the method have broad application prospects in fields such as perovskite solar cells, photocatalysis, and gas sensing.

The invention discloses a process for producing titanium-zirconium-hafnium series metal through continuous reduction, which comprises the following steps: in an inert atmosphere, heating a reactor to a reaction temperature, adding metal magnesium, and then continuously adding tetrachloride at a constant high speed to carry out reduction reaction. In the reaction process, magnesium chloride melt is continuously or intermittently discharged, and metal magnesium is supplemented to maintain the reaction; meanwhile, the generated sponge titanium is continuously moved out and conveyed to a collector through a conveying device directly communicated with the reactor. The whole process of feeding, reacting, discharging and product moving-out is continuous, a traditional sequencing batch production mode is subverted, the titanium tetrachloride feeding speed can be stably kept at a high level (for example, the titanium tetrachloride feeding speed is larger than or equal to 1600 kg / h), the production efficiency is remarkably improved compared with a traditional process, meanwhile, stability and excellent product quality are guaranteed, the automation degree is high, and the production cost is low. And centralized recycling of reaction waste heat can be realized.

The invention discloses a preparation method of a 3D graphene-loaded tin oxide composite material. The preparation method comprises the following steps: preparing a precursor solution from graphene oxide, tin tetrachloride pentahydrate and ascorbic acid; dropwise adding a lauryl sodium sulfate solution into the precursor solution, and fully mixing to obtain a mixed solution; transferring the mixed solution into a glass bottle, and sealing and heating to promote the self-loading process of the solution; performing freeze thawing / 80 DEG C thermal reduction treatment on the preformed sample to form a preliminary composite material of tin oxide and graphene; repeatedly washing the sample subjected to thermal reduction by using ethanol to remove residual impurities, and then carrying out drying treatment; and carrying out annealing heat treatment on the dried sample in a nitrogen atmosphere to obtain the 3D graphene-loaded tin oxide composite material. The preparation method of the 3D graphene loaded tin oxide composite material provided by the invention is simpler in preparation process, lower in cost and suitable for large-scale industrial production.

The present application relates to the technical field of chemical synthesis, in particular to a method for inhibiting poisoning of a proton exchange membrane in one-pot production of p-chlorophenylhydrazine, which uses p-chloronitrobenzene as a substrate and tin dichloride for reduction reaction to realize one-pot synthesis process of p-chlorophenylhydrazine.The method does not need intermediate separation steps, can directly feed materials, effectively reduces loss of raw materials, and realizes continuous reduction of tin tetrachloride by reasonable inhibition of poisoning of the proton exchange membrane, recycles tin dichloride, and re-puts it into the nitrobenzene reduction step.Compared with the traditional method, the method solves the yield reduction problem caused by p-chlorophenylhydrazine preparation in steps and purification, solves the problem of poisoning of the proton exchange membrane by phenylhydrazine hydrochloride, is suitable for industrial production environment, improves the product yield, reduces environmental pollution, has low cost, and is suitable for efficient continuous production of important chemical intermediate p-chlorophenylhydrazine.

The invention relates to a process for recovering silicon in the form of tetrachloride, in which biochar with a silicon content, expressed in wt.% of elemental silicon, of at least 1 wt.% is reacted with elemental chlorine at a temperature of 350 to 900°C and the silicon tetrachloride formed is separated from the exhaust gas stream, preferably by condensation.

The invention discloses a method for preparing a composite photocatalyst by resource utilization of magnesium slag or waste liquid, which comprises the following steps of: pretreating magnesium slag or waste liquid serving as a raw material to obtain a magnesium salt solution; and uniformly mixing a magnesium salt solution with a tin tetrachloride solution and a urea solution to obtain a mixed solution, carrying out a hydrothermal reaction, and carrying out post-treatment. The composite photocatalyst is a specific amount of magnesium-doped tin dioxide material and can be directly used for degradation of VOCs (Volatile Organic Compounds). According to the method, resource utilization of the magnesium slag or the waste liquid is realized, and the method is environment-friendly and has a good removal effect on typical environmental pollutant methylbenzene. The composite photocatalyst is prepared by adopting a hydrothermal method, the preparation process is simple, the production cost is low, and the operation is convenient.