34 results about "Dimethyldichlorosilane" patented technology

The invention relates to high-heat-resistance polypropylene and a preparation method thereof, and belongs to the technical field of high polymer materials. The preparation method comprises the following steps: carrying out Michael addition reaction on 2-sulfydryl-1, 3-propylene glycol and vinyl dibutyl borate to prepare dihydric alcohol containing thioether and phosphate, and carrying out polymerization reaction on 1, 12-dodecanediol, boric acid ester dihydric alcohol and dimethyldichlorosilane to obtain the flame retardant. A polymer containing a borate group, a thioether group, organic silicon and a dodecane glycol ester group is prepared, the polymer is used as a heat-resistant toughening additive of polypropylene, the borate group and the organic silicon can improve the heat resistance and flame retardance of the polypropylene, and the thioether group and the dodecane glycol ester group can provide flexibility; therefore, the polypropylene is ensured to have good mechanical strength, heat resistance and flame retardance at the same time.

This invention relates to a method for strengthening the formation of Si8Al6Fe4Ca from industrial silicon melt through stepped solidification, belonging to the technical field of high-value utilization of industrial silicon. Addressing the practical problems of uncontrollable solidification rate, incomplete intermetallic compound transformation, and random precipitation of intermetallic compounds in the air-cooling casting process of industrial silicon melt, as well as low selectivity and primary conversion rate of dimethyldichlorosilane when synthesizing organosilicon monomers using industrial silicon as raw material, this invention casts the oxidized and refined silicon melt into a mold with controllable cooling. Through optimization of solidification process parameters, stepped variable-rate solidification is achieved to reduce the content of harmful FeSi2 / CaSi2 phases in industrial silicon products and promote the full conversion of harmful phases to Si8Al6Fe4Ca, Si2Al2Ca, and Si2Al3Fe. This invention has the advantages of fully utilizing and saving energy, low infrastructure investment, simple process flow, high operability, and no environmental pollution.

This invention discloses a modified polysilazane, a two-component silicone sealant, and a method for preparing the same. The modified polysilazane is prepared through a nucleophilic substitution reaction of dimethyldichlorosilane, vinyltrichlorosilane, and ethylenediamine. The two-component silicone sealant prepared using the modified polysilazane of this invention significantly improves its hardness under sealed conditions without adversely affecting its curing and performance. Furthermore, it requires a small amount and is highly practical. The two-component silicone sealant prepared using the modified polysilazane of this invention exhibits high hardness retention under sealed conditions, significantly slows down the reversion phenomenon, and maintains good mechanical properties and adhesion even after curing at 90°C under sealed conditions. It also demonstrates excellent resistance to reversion under fully sealed conditions.

An on-line moisture detection device for dimethyl dichlorosilane hydrolysis hydrogen chloride comprises a gas conveying pipeline, a cooler, a dryer and a compressor are sequentially arranged on the gas conveying pipeline in the conveying direction, a gas inlet branch pipe is arranged on the gas conveying pipeline between the cooler and the dryer and connected to a moisture detection mechanism, and the moisture detection mechanism is connected with the compressor. And the gas conveying pipeline between the dryer and the compressor is provided with another gas inlet branch pipe, and the gas inlet branch pipe is connected to another moisture detection mechanism. By adopting the structure, the moisture content of the product hydrogen chloride can be monitored and processed in real time, the moisture content in the product hydrogen chloride is effectively controlled, and the compressor is prevented from being damaged.

The invention discloses a nano titanium dioxide reinforced plastic compatilizer and a preparation process thereof, and belongs to the technical field of high-molecular polymers. The invention is used for solving the technical problems in the prior art that in order to improve various properties between polypropylene and an inorganic material compound, the doped plastic compatilizer has excessive components, resources are wasted, and the environment is not protected. The preparation process of the nano titanium dioxide reinforced plastic compatibilizer comprises the following steps: melting, blending and extruding a multi-paraffin polymer and a grafting monomer to form the nano titanium dioxide reinforced plastic compatibilizer, the multi-paraffin polymer is obtained through reaction of glucosamine lauroyl and dimethyldichlorosilane in an alkaline environment, and the grafting monomer is obtained through reaction of a cyclization compound, nano silicon dioxide dispersion liquid and an EDC-NHS activation system.

The application relates to the technical field of composite materials, and particularly relates to a silicon carbide fiber composite core wire and a preparation method. Dimethyldichlorosilane is obtained to carry out dechlorination polymerization, polydimethylsilane is generated, high-temperature and high-pressure cracking rearrangement is carried out, and polycarbosilane is obtained; the polycarbosilane is melted and extruded through a spinning hole to obtain continuous polycarbosilane original fibers, the continuous polycarbosilane original fibers are crosslinked to obtain crosslinked fibers, high-temperature cracking is carried out, and the crosslinked fibers are converted into inorganic silicon carbide fiber bundles; the silicon carbide fiber bundles are immersed in a high-temperature resistant resin glue solution and enter a heated pultrusion mold to be pultruded into a silicon carbide fiber composite core rod; inner layer aluminum wires are twisted outside the silicon carbide fiber composite core rod, and outer layer aluminum wires are twisted outside the inner layer aluminum wires to obtain the silicon carbide fiber composite core wire. The prepared composite core wire has the outstanding advantages of high strength, high modulus, high-temperature resistance, oxidation resistance, corrosion resistance, a low thermal expansion coefficient and large conveying capacity, and has important economic benefits in power transmission line capacity increasing and reconstruction projects.

The invention provides high-purity polydimethylsilane and a preparation method thereof, and the preparation method comprises the following steps: adding dimethyldichlorosilane and alkali metal into a benzene solvent under the protection of inert gas, and reacting at high temperature to obtain a product; adding alcohol into the product, neutralizing unreacted raw materials, and then filtering to obtain crude polydimethylsilane; providing a cleaning container provided with two layers of filter screen assemblies, and adding the crude polydimethylsilane between the two layers of filter screen assemblies; a cleaning solvent is added into the cleaning container to be higher than the upper-layer filter screen assembly, and cleaning is conducted; a part of liquid in the cleaning container is discharged from the upper part of the upper-layer filter screen assembly, and then the residual liquid is discharged from the lower part of the lower-layer filter screen assembly; and repeating for multiple times, and finally evaporating to obtain the high-purity polydimethylsilane. According to the method, the content of oxygen-containing silane, chloride ions and alkali metal ions in the polydimethylsilane can be reduced, and the high-purity polydimethylsilane with the oxygen content lower than 0.5%, the chloride ion content lower than 20 ppm and the alkali metal ion content lower than 20 ppm is obtained.

The invention discloses a methyl chlorosilane high-boiling residue cracking catalyst as well as a preparation method and a use method thereof, and belongs to the technical field of catalysts. The preparation method specifically comprises the following steps: S1, adding gamma-Al2O3 and 3-aminopropyltrichlorosilane into anhydrous xylene, stirring for a certain time at normal temperature under the protection of nitrogen, heating to a reflux state, carrying out reflux stirring for a certain time, filtering while hot, washing, and carrying out vacuum drying to obtain amino-functionalized gamma-Al2O3; and S2, adding the amino-functionalized gamma-Al2O3 obtained in the step S1 into absolute ethyl alcohol dissolved with AlCl3 and a cocatalyst, stirring for a certain time under the protection of nitrogen and at room temperature, filtering, and drying in vacuum to obtain the AlCl3 catalyst immobilized on the amino-functionalized gamma-Al2O3. The catalyst can be used as a catalyst for preparing dimethyl dichlorosilane through cracking of methyl chlorosilane high-boiling residues, reaction is carried out under the conditions of low temperature and low pressure, and the highest cracking conversion rate of the methyl chlorosilane high-boiling residues can reach 99.4%; and the yield of the dimethyl dichlorosilane can reach up to 88.6%.

The invention relates to the technical field of thermosetting materials, and discloses a preparation method of benzoxazine and bismaleimide transparent resin alloy, which comprises the following steps: preparing required materials: mixing bismaleimide and benzoxazine according to a certain proportion, adding a proper amount of solvent, and stirring for a period of time to form a uniform mixture; adding a proper amount of cross-linking agent into the mixture, fully stirring, casting a blend solution on a glass plate pretreated with dimethyldichlorosilane, drying at 50 DEG C for 4-6 hours, and then respectively carrying out heat treatment at different temperatures for 1-3 hours to obtain an alloy membrane; and testing the performance of the alloy film. According to the process, bismaleimide and benzoxazine are used as main raw materials, and the transparent bismaleimide resin alloy material with excellent performance is prepared through a specific formula and process steps. The alloy material not only has high transparency and excellent heat resistance, but also has relatively high mechanical strength and chemical stability.

The invention provides a method for preparing methyl chlorosilane by using methyl chlorosilane high-boiling cracking residual liquid. The method comprises the following steps: by taking methyl chlorosilane high-boiling residue cracking raffinate, methyl trichlorosilane and trimethyl chlorosilane as main raw materials and Al2O3-V2O5-WO3 as a catalyst, carrying out cracking disproportionation in a high-pressure reaction kettle under the conditions of heating and pressurizing, and rectifying and separating a reaction product to obtain the dimethyl dichlorosilane. According to the method, the high-value dimethyldichlorosilane can be prepared from the hazardous waste methyl chlorosilane high-boiling cracking residual liquid through the disproportionation reaction, so that cyclic utilization of the high-boiling residue cracking residual liquid is realized, and the problems that the high-boiling residue cracking residual liquid is large in discharge amount, difficult to treat and the like are solved; and through catalysis of Al2O3-V2O5-WO3, the selectivity of dimethyldichlorosilane can be improved, toxic aniline substances carried in high-boiling residue cracking raffinate can be adsorbed, and the problems of environmental pollution and the like are solved.

The present application belongs to the field of dimethyldichlorosilane concentrated acid hydrolysis reaction in the organic silicon industry, and particularly relates to a dimethyldichlorosilane concentrated acid two-stage hydrolysis reaction process. The process comprises the following specific steps: dimethyldichlorosilane is subjected to a first-stage hydrolysis reaction with recycled saturated hydrochloric acid and water, and an additive is added; purification and drying are performed, and the purified siloxane is subjected to a second-stage reaction in a second-stage reactor; after the second-stage reaction is completed, the mixture is subjected to oil-water separation, and the hydrolyzate is subjected to a washing section to obtain a final product. The dimethyldichlorosilane provided by the present application is subjected to two-stage hydrolysis reaction, the content of chlorine-terminated groups in the generated hydrolyzate is greatly reduced, the acid content is low, and the quality of the hydrolysis product is high. The new process provided by the present application adopts a two-stage reaction system, solves the problems of high chlorine-terminated group content, hydrogen chloride gas containing dimethyl and hydrolyzate, and obtains high-quality hydrolyzate, and the reaction system maintains a slight positive pressure, which does not inhibit the dimethyl hydrolysis reaction.

This invention relates to a novel process for manufacturing a SiC-coated body by depositing silicon carbide (SiC) on a graphite substrate using dimethyldichlorosilane (DMS) as a silane source in a chemical vapor deposition method. Another aspect of the invention relates to novel SiC-coated bodies obtainable through the novel process of this invention, and to their use in manufacturing articles for high-temperature applications, substrates and reactors, semiconductor materials, and wafers.

The invention provides a preparation method of an AG glass anti-dazzle coating based on a nano microstructure, and relates to the technical field of anti-dazzle coating preparation.The preparation method of the coating comprises the following steps that a coating A, a coating C and a coating B are sprayed on AG glass in a layered mode, so that a layered anti-dazzle coating structure is formed, modified nano silicon dioxide is added into the coating B, and the anti-dazzle coating is obtained. According to the present invention, the anti-glare paint film is obtained by using the dimethyldichlorosilane as the modifier to modify the nano-silica, such that the good matting effect is generated on the basis of the assurance of the glossiness of the paint film, and the basic nano-scale concave-convex structure is constructed between the layers so as to ensure the core anti-glare ability on the basis of the adhesion effect after the anti-glare paint is coated; and visual fatigue caused by direct strong light is avoided.

The present application relates to the process and system for reducing the acid value of dimethyldichlorosilane hydrolysate in the separation and washing process. The three-stage coalescer is arranged, the acidic hydrolysate of dimethyldichlorosilane enters the system from the first-stage coalescer, the process water enters the system from the third-stage coalescer, the acidic hydrolysate is mixed with dilute hydrochloric acid or process water in each coalescer, the oil-water two-phase separation is completed through multiple washing and coalescing, and the acid value of the hydrolysate is reduced; each coalescer comprises two series static mixers, a group of pre-filters, and a large coalescer, the coalescer is in the shape of Z, and each coalescer contains four filter cores. Through repeated tests, the modified polyvinylidene fluoride filter core of Dowell is finally selected, and after the continuous three-stage coalescer treatment, the acid value of the dimethyldichlorosilane hydrolysate can be reduced to below 10 PPM.

The invention relates to a high-performance organic silicon packaging adhesive for a photovoltaic module, the packaging adhesive is an organic high-molecular compound taking a silicon-oxygen bond as a main chain, and a colloidal elastomer is formed after the packaging adhesive is cured; the working temperature range of the packaging adhesive is-55 DEG C to 250 DEG C, the light transmittance of the packaging adhesive in a visible light range is not lower than 92%, and after the packaging adhesive is aged for 1000 hours under the double-85 test conditions of 85 DEG C and 85% relative humidity, the light transmittance retention rate is larger than 95%; the packaging adhesive is prepared from a monomer mixture containing dimethyl dichlorosilane and methyl trichlorosilane through high-temperature reaction, hydrolysis and condensation processes under the action of a composite catalytic system of copper and various high polymer materials, and finally a network polymer with linear and cross-linked structures is formed. The core purpose of the invention is to provide a revolutionary photovoltaic packaging material which is high in light transmittance, extremely stable in chemical property, capable of greatly improving the reliability, the service life and the power generation efficiency of a component, and environment-friendly and recoverable.

The invention relates to the technical field of organic silicon chemical industry, and discloses a method for preparing an organic silicon monomer from low-grade silicon powder based on element regulation and control, which comprises the following steps: step 1, pretreating the low-grade silicon powder: crushing the low-grade silicon powder, adding a pretreating agent, reacting for 2-3 hours at the temperature of 60-80 DEG C and the stirring speed of 200-300r / min, and then filtering, washing and drying to obtain pretreated silicon powder; step 2, preparation of the element regulating agent: mixing the main regulating agent and the auxiliary regulating agent according to the mass ratio of (5-7): 1, adding the dispersing agent, and dispersing at the rotating speed of 3000-5000r / min for 30-40 minutes to obtain the element regulating agent. Compared with the prior art, the method has the advantages that harmful impurities are effectively removed by performing targeted pretreatment and element regulation on the low-grade silicon powder, and beneficial catalytic components are introduced, so that high-efficiency and high-selectivity utilization of the low-grade silicon powder is realized, and the high-content dimethyldichlorosilane monomer is prepared.

The invention discloses a method for preparing hydroxyl silicone oil by using a micro-channel reactor, which comprises the following steps: respectively pumping dimethyldichlorosilane and a hydrolysis medium into the micro-channel reactor by a plunger pump to carry out primary hydrolysis reaction, and adjusting the reaction pressure in the first micro-channel reactor by a back pressure valve; separating an oil-water mixture after the reaction into a hydrolysate and a water-phase medium containing ammonium chloride through a phase separator; by utilizing the excellent mass transfer and heat exchange performance of the micro-channel reactor, not only is the reaction time greatly shortened, but also compared with the traditional kettle reaction, the loss of dropwise added feed and the risk that the raw material dimethyldichlorosilane and the hydrolysis medium are subjected to violent hydrolysis reaction to release heat and are easy to spray are reduced, the safe production of the hydroxyl silicone oil is realized, and the production cost is reduced. The method has the advantages of high efficiency, energy conservation, easiness in control, few three wastes and the like.

The present invention relates to a method for preparing chlorosilanes, the method comprising the steps of: preparing a reactant comprising methylchlorosilane synthesis residue and methyldichlorosilane (MH); and reacting the reactant in the presence of an alumina catalyst to form a product comprising dimethyldichlorosilane (M2), methyltrichlorosilane (M1), and trimethylchlorosilane (M3), wherein the reaction is carried out at 300-500°C for 1-3 minutes.

The utility model discloses an octamethylcyclotetrasiloxane production device, which belongs to the field of distillation and comprises a distillation tower, a heating device positioned below the distillation tower, a condensation pipe positioned at the output end of the distillation tower and a storage bottle for receiving condensed liquid. Compared with the prior art, the condensation device has the advantages that the condensation pipes for receiving different evaporation temperatures are uniformly connected through the shunting pipelines, and the opening and closing of the condensation pipes are controlled through the electromagnetic on-off valves; the gas concentration monitor for detecting the dimethyldichlorosilane is mounted at the top end of the shunting pipeline, and when the concentration is reduced to a certain range, the distillation tower is preheated and heated to enable the temperature of the distillation tower to be close to 173 DEG C, so that the effect that the distillation tower can be recovered without influencing the volatilization of the dimethyldichlorosilane is achieved. The octamethylcyclotetrasiloxane in the next stage can be ensured to quickly enter the distillation stage.

The application provides a method for catalytically cracking organosilicon high-boiling substances. The method comprises the following steps: contacting an organosilicon high-boiling substance raw material with a cracking catalyst to generate a cracking reaction; the reaction temperature of the cracking reaction is not lower than 500 DEG C; the cracking catalyst comprises a carrier and a metal active component loaded on the carrier, the metal active component at least comprises one or more of Fe, Zn, Ni, Ti and Mo, the mass content of the metal active component in the cracking catalyst is not less than 1%, the carrier at least comprises a molecular sieve, and the mass content of the carrier in the cracking catalyst is not less than 10%. The catalyst used in the cracking reaction of the application does not contain heavy metals, and has high selectivity to methyl chlorosilane monomers such as monomethyltrichlorosilane, dimethyldichlorosilane and trimethylmonochlorosilane, especially can effectively improve the selectivity of dimethyldichlorosilane, and has mild and efficient reaction conditions, high catalytic efficiency.

The invention belongs to the technical field of coal mine safety, and particularly relates to a nano anti-drag material as well as a preparation method and application thereof. The preparation method comprises the following steps: dispersing nanoparticles in an organic solvent to form a dispersion liquid; adding a silane coupling agent and a performance additive into the dispersion liquid to carry out surface modification reaction; and after the reaction is finished, centrifugally washing, drying and grinding to obtain the surface-modified nano anti-drag material. Through surface modification of dimethyldichlorosilane, the problem that particles such as nano silicon dioxide are easy to agglomerate in an organic medium is solved, the process is simple and controllable, and the modification method is mild in condition, simple in step, good in repeatability and easy to realize stable production and quality control. In coal mine coal seam water injection application, dust and gas disaster risks are reduced in an energy head and high efficiency mode, miner health and production safety are guaranteed, erosion and abrasion to pumps, valves and pipelines are reduced, maintenance cost is reduced, social benefits are huge, and application is wide.

The present invention relates to a new process for manufacturing SiC-coated bodies by depositing silicon carbide (SiC) on a graphite substrate using dimethyldichlorosilane (DMS) as a source of silane in a chemical vapor deposition process. Another aspect of the invention relates to a novel silicon carbide coated body obtainable by the novel process of the invention and to the use thereof for the manufacture of articles for high temperature applications, susceptors and reactors, semiconductor materials and wafers.

The invention provides a flame-retardant water-based paint. The flame-retardant water-based paint comprises a water-based hydroxyl acrylic emulsion, a flame retardant and modified nano silicon dioxide, wherein at the temperature of 25 DEG C, 20-35 parts of the flame retardant are dissolved in 100 parts of water; the modified nano silicon dioxide is prepared from fumed silica and dimethyldichlorosilane through a reaction. By regulating and controlling the solubility of the flame retardant in water, the performance of the flame retardant in a water-based hydroxyl acrylic emulsion paint film is optimized. Low solubility may influence the content and dispersion of the flame retardant and reduce the flame retardant effect; and if the solubility is high, the flame retardant is easy to migrate to the surface of a paint film along with water to damage the water resistance. And by balancing the solubility, the water resistance can be improved while the flame retardant property is maintained. In addition, modified nano silicon dioxide is introduced, surface precipitation of the flame retardant can be inhibited, dispersion stability of the flame retardant is improved, and water resistance of a paint film is further enhanced by means of low surface tension of the flame retardant.

The invention discloses a preparation method of low-viscosity hydroxyl silicone oil, which comprises the following steps: mixing dimethyldichlorosilane and acetic anhydride according to a certain molar ratio, uniformly stirring, continuously stirring and reacting at room temperature, separating out unreacted raw materials and byproducts through an atmospheric and vacuum distillation device after the reaction is finished, then obtaining an intermediate product dimethyldiacetoxysilane, and finally obtaining the low-viscosity hydroxyl silicone oil. The method comprises the following steps: adding sodium carbonate or a mixed aqueous solution of sodium carbonate and sodium bicarbonate into a dimethyldiacetoxysilane hydrolysis reaction kettle in proportion, neutralizing and hydrolyzing, standing for layering, taking out an upper oil phase, namely a low-viscosity hydroxyl silicone oil crude product, and dehydrating the low-viscosity hydroxyl silicone oil crude product by using anhydrous calcium chloride. The preparation method of the low-viscosity hydroxyl silicone oil, provided by the invention, has the advantages that the energy consumption is reduced, the risk in the reaction process is greatly reduced, the additional value of the product is improved while the three wastes are reduced, and the environmental risk caused by the loss in the organic solvent production process is reduced.

The invention relates to the technical field of thermosetting materials, and discloses a bisphenol A type benzoxazine and bismaleimide transparent resin alloy preparation method which comprises the following steps: preparing required materials; and casting the blend solution on a glass plate pretreated with dimethyldichlorosilane, and drying at 50 DEG C for 4-6 hours. Then respectively carrying out heat treatment for 1-3 hours at different temperatures to obtain an alloy film; and the prepared alloy films with different mixing ratios and different heat treatment temperatures are subjected to performance testing. According to the process, bismaleimide and bisphenol A type benzoxazine B-a are used as main raw materials, and the transparent bismaleimide resin alloy material with excellent performance is prepared through a specific formula and process steps. The alloy material not only has high transparency and excellent heat resistance, but also has relatively high mechanical strength and chemical stability.

The invention discloses a block copolymer well wall reinforcer rich in positive charge anchor points as well as a preparation method and application thereof, and belongs to the technical field of new materials of drilling engineering. The well wall reinforcer is a block copolymer formed by generating a silicon-oxygen bond polymer through an acid-catalyzed hydrolytic polymerization reaction and sequentially grafting a hydrophilic group and introducing a quaternary ammonium salt group. The silicon-oxygen bond polymer is prepared from silane monomers including dimethyldichlorosilane, dimethyldimethoxysilane or dimethyldiethoxysilane through a hydrolytic condensation reaction. The preparation method comprises the following steps: preparing the silicon-oxygen bond polymer from the silane monomers including dimethyldichlorosilane, dimethyldimethoxysilane or dimethyldiethoxysilane; the hydrophilic group is polyethylene glycol or polypropylene glycol, and the quaternary ammonium salt group is dimethyl diallyl ammonium chloride, hydroxyethyl trimethyl ammonium chloride or hydroxyethyl triethyl ammonium chloride. The well wall reinforcing agent is good in well wall adsorbability and chemical stability, can keep efficient leaking stoppage performance in a high-temperature and high-pressure environment, and effectively reduces scouring erosion of drilling fluid to a well wall; the drilling fluid is excellent in performance in low-permeability fractured oil reservoirs and pore type and fractured leakage stratums, and the safety and efficiency of drilling operation are improved.

The invention provides a process method and a catalyst for synergistic treatment of organic silicon by-products, and the method comprises the following steps: adjusting the ratio of the organic silicon by-products, mixing a methyl-containing carbon source into the organic silicon by-products, and carrying out catalytic cracking reaction on the obtained mixed material under the action of cracking gas to obtain the organic silicon by-products. A catalytic product containing a dimethyl dichlorosilane monomer and a trimethylmonochlorosilane monomer is obtained; wherein the active element of the catalyst comprises any one or a combination of at least two of aluminum, zinc, copper, calcium, barium or magnesium. Cooperative treatment of various by-products in the production process of the organic silicon monomer is achieved, directional reconstruction of silicon, methyl and chlorine functional groups is achieved, and high-value dimethyldichlorosilane and trimethylchlorosilane monomers are prepared. The utilization rate of the synergistic treatment of the organic silicon by-products exceeds 90%, the selectivity of M2 exceeds 50%, and the selectivity of M3 exceeds 20%, so that the high-value utilization level of the by-products in the organic silicon industry is greatly improved, and a way for reducing the cost and improving the efficiency is provided.

This invention relates to a method for preparing industrial silicon powder for organosilicon monomer synthesis from high-speed rail industrial silicon melt, belonging to the field of industrial silicon production technology. This invention addresses the practical problem of excessive Fe impurities in the melt after ladle refining of silicon melt, leading to high FeSi2 content in industrial silicon products and low selectivity for dimethyldichlorosilane when synthesizing organosilicon monomers using this industrial silicon as a raw material. By obtaining the content of the main metallic impurities in the high-speed rail type silicon melt after ladle refining, a quantitative alloying agent Al is added to adjust the composition of the silicon melt. After heat preservation, the melt is poured and the solidification rate is controlled to form a large amount of beneficial Si8Al6Fe4Ca phase, thus preparing industrial silicon powder for organosilicon monomer synthesis, thereby improving the selectivity and activity of the organosilicon monomer synthesis process. This invention has advantages such as no special requirements on the impurity content of the silicon melt, full utilization and energy saving, low infrastructure investment, simple process flow, high operability, and no environmental pollution.

The invention discloses a polyethylene composition as well as a preparation method and application thereof. The polyethylene composition is prepared from the following components in parts by weight: 69 to 91 parts of polyethylene, 0.8 to 1.2 parts of fumed silica, 10 to 15 parts of brominated flame retardant, 3 to 5 parts of antimony flame retardant and 5 to 10 parts of metal hydroxide, the fumed silica is fumed silica of which the surface is modified by a methylsilane organic matter; the nitrogen adsorption specific surface area of the fumed silica is 100-200m < 2 > / g; and the methylsilane organic matter is selected from at least one of monomethyl dichlorosilane, dimethyl dichlorosilane, polydimethylsiloxane and hexamethylsilazane. The polyethylene composition provided by the invention has excellent flame retardance, low heat release and low smoke amount; in addition, the composition also has excellent bending and whitening resistance.