39results about How to "Lower melt temperature" patented technology

The invention provides a method for directionally solidifying and purifying polycrystalline silicon by adopting ferro-silicon alloy and relates to a purifying method of polycrystalline silicon. The method comprises the following steps of putting industrial silicon powder into hydrochloric acid for soaking and then washing with deionized water; putting silicon powder and iron powder into a graphite crucible, putting the graphite crucible into a directional solidification furnace, closing a furnace cover, vacuum-pumping to below 10 Pa and introducing argon; opening an inductive heating power supply and carrying out heat preservation after the temperature in the graphite crucible reaches 1570-1650 DEG C; starting a directional solidifying lifting device for directional solidification and removing impurities in the silicon to obtain a cast ingot; putting the cast ingot into a vacuum annealing furnace for annealing treatment and then cooling the furnace to a room temperature to obtain an alloy cast ingot; and taking out the alloy cast ingot and cutting 20-40 percent of the upper part of the alloy cast ingot and obtaining a remainder, i.e. the polycrystalline silicon directionally solidified and purified by adopting the ferro-silicon alloy. The method has the advantages of low equipment cost, simple and feasible process, good purifying effect and very wide market prospect in the production field of the solar grade polycrystalline silicon.

A grooved barrel extruder, the inner surface of the barrel liner (10) and the outer surface of the screw (13) are both cylindrical or conical; the volume of the barrel liner groove (11) is extruded along the The direction gradually decreases; the screw (13) is a separation type screw, the volume of the screw solid-phase channel (16) gradually decreases along the extrusion direction, and the volume of the screw liquid-phase channel (12) gradually increases along the extrusion direction; When the screw (13) rotates, the material in the barrel bushing groove (11) and the material in the screw solid-phase channel (16) always maintain friction between solid phases, and interface melting occurs at the screw melting section (21), and the molten The material is continuously dragged into the screw liquid-phase channel (12), the solid-phase material in the screw solid-phase channel (16) and the barrel liner groove (11) decreases, and the molten material in the screw liquid-phase channel (12) increases ; The completely melted material is re-collected to the screw groove (18) of the melting section of the screw, and the material is stably transported through the melt conveying section.

The present invention relates to the technical field of directional solidification, in particular to a multi-mode excited deep subcooled directional solidification device and method, which includes a reaction furnace, a smelting device, a feeding device, an excitation device, a drawing rod and a drawing device, and the feeding device is used for Add purifying agent to the crucible during the heat melting process; the excitation device includes an excitation chamber that can be filled with liquid metal, a water-cooled ring layer and a liquid level controller that communicates with the excitation chamber, and the liquid level controller is used to control the liquid level of the liquid metal in the excitation chamber ; The pulling device can pull at least a part of the crucible into the excitation chamber at a predetermined speed range through the pulling rod. This device realizes the deep subcooling of the melt through the combination of glass purification and cyclic superheating, and ingeniously combines smelting, liquid metal / water dual cooling and drawing devices. Different modes can be selected to stimulate the directional solidification of the deep supercooled melt, so that it can Obtain deep supercooled directional solidification castings with different microstructure and performance characteristics to meet more research and application needs.

The invention discloses a magnesium-nickel master alloy and a preparation method thereof. The preparation method includes: taking magnesium ingots and nickel blocks and drying them; putting part of the magnesium ingots into a non-vacuum intermediate frequency electromagnetic induction furnace for heating, and passing through SF when the magnesium ingots start to melt 6 with N 2 The mixed gas; the magnesium ingot is completely melted and then put into the nickel block, and continuously fed with SF 6 with N 2 After the nickel block is fully reacted, stir the melt fully; close the non-vacuum intermediate frequency electromagnetic induction furnace, add the remaining magnesium ingots to the melt to cool down the melt, stir evenly, and cast. The present invention uses ordinary magnesium ingots and nickel as raw materials, utilizes ordinary non-vacuum intermediate-frequency electromagnetic induction furnaces, and controls the smelting process to produce magnesium-nickel alloys with good surface quality, uniform composition, and low slag inclusions, and can be preserved in conventional environments. It takes a long time; the production process is simple to operate, the magnesium alloy smelting has less burning loss, the equipment requirements are low, the product quality is stable, and mass production can be realized.

The invention discloses PP-R (polypropylene) pipe production equipment. The PP-R (polypropylene) pipe production equipment comprises an extruder, a machine head arranged on the extruder, and a forming head arranged at an outlet end of the machine head, wherein the machine head comprises a core model, a mouth model, an adjusting seat, a core model afterbody, an outer model afterbody, and a core model seat; the core model afterbody comprises a flange and a core model section, the core model section of the core model afterbody is conical and is inserted into an inner hole of the outer model afterbody, the core model afterbody is internally provided with a feeding inlet, a spiral chute is arranged in the outer surface of the core model section of the core model afterbody, the depth of the spiral chute is gradually shallower from the head part to the tail part, and the head part of the spiral chute is communicated with the feeding inlet by a distribution hole arranged in the core model afterbody. When materials pass through the spiral chute, the melt flow is changed from the axial direction to the radial direction, thereby playing a good mixing effect and effectively eliminating the stress memory property of a melt.

The invention discloses a cooling and inner wall lubricating device for a magnesium alloy continuous casting liquid-solid converter. The cooling and inner wall lubricating device comprises an inner wall which is formed by splicing a plurality of layers of curves, and a back plate is matched with the inner wall to form a junction face in which cooling water can be introduced. The inside of the junction face is divided into a plurality of cooling areas from top to bottom, and each cooling area is provided with an independent water inlet and a water outlet. Gaps are reserved between the splicing faces, formed by the curves, on the inner wall, and the gaps communicate with lubricating oil through holes formed in the back plate to provide a lubricating channel between a magnesium alloy coagulating shell and the inner wall. According to the cooling and inner wall lubricating device, cooling and lubricating are both combined into the inner wall and the back plate, the cooling water can be introduced into the junction face to cool the inner wall, and the heat of molten state magnesium alloy in the inner wall is taken away, so that the temperature of a contact part is lowered to be below a solidification level, and a liquid-solid converting effect is achieved. The friction force of a casting blank shell and the inner wall of a coagulator can be lowered, the shell removing effect of casting blanks is improved, and the throwing speed of the casting blanks is improved.

The invention relates to a method for preparing ferroboron based on a thermit self-propagating gradient reduction and slag-washing refining, and belongs to the technical field of ferroalloy. The method comprises the steps that after raw materials are preprocessed, by mass, 1.0 part of boric anhydride, 1.33-4.49 parts of Fe2O3 powder, 1.22-2.29 parts of aluminum power and 0.6-3.2 parts of CaO are weighed; then a thermit self-propagating reaction is conducted by adopting the mode of gradient feeding to obtain high temperature molten liquid, and gradient reduction smelting is conducted; after feeding is completed, thermal-insulation melt separation is conducted; and CaO-CaF2 base refining slag is added into the high temperature molten liquid, and the ferroboron is obtained after slag is removed. The gradient-feeding method achieves controlling over the reaction process and the temperature and thorough reducing of metallic oxides, and moreover, the smaller the gradients of the aluminum coefficients are, the fewer aluminum residues in the alloy molten liquid are; slag-washing refining achieves thorough chemical reaction of a slag-metal interface and slag-metal separation, and the recovery rate of boron is enhanced; and meanwhile, the temperature of the molten liquid is reduced, the system reaction heat is utilized, and energy consumption is reduced.

The invention discloses a matte polyvinyl chloride resin with high gel content and a preparation method thereof. The production steps include: S1, measuring raw materials; S2, soaking the matte polyvinyl chloride resin for 1 to 4 hours; S3, adding a crosslinking agent The body and dispersant continue to soak for 1 to 3 hours; S4, adding part of the initiator to react; S5, adding the remaining initiator to continue the reaction; S6, adjusting the pH of the system, adding a stabilizer; S7, increasing the reaction temperature before the end of the reaction, and adding calcium stearate and stearyl alcohol; S8, adding a terminator, removing residual monomers by steam stripping, and centrifugal drying to remove moisture to obtain a matte polyvinyl chloride resin. Its advantages are: use low gel content matting polyvinyl chloride resin as raw material, prepare high gel content matting polyvinyl chloride resin under normal pressure or low pressure conditions, and avoid Produce implosion, reduce the "fish eye" produced in the production of extinction PVC, improve the extinction effect, improve the thermal stability of the product, and improve the processing performance.

The invention discloses continuous casting equipment and a continuous casting method for magnesium alloy and aluminum alloy ingot blanks. The continuous casting equipment comprises a mold and a dummy ingot block, a liquid level control lever, an internal cooling device, an oil way lubricating system and a split plate are further arranged in the continuous casting equipment, the internal cooling device comprises an internal cooling core pipe, an internal cooling head, a water inlet pipe, a sealing ring, a vibration head, an eccentric wheel, a variable-speed motor, a shell, a water outlet pipe, a spring and the like, the eccentric wheel is driven by the variable-speed motor, the upper end of the vibration head is connected with the eccentric wheel, the lower end of the vibration head and the upper end of the internal cooling head are fixedly connected into a whole and placed in a slide way defined by an upper plate and a lower plate, and the water inlet pipe is communicated with the internal cooling core pipe, an inner cavity of the internal cooling head and the water outlet pipe. When the continuous casting equipment for the magnesium alloy and aluminum alloy ingot blanks is operated, the internal cooling head of the internal cooling device is placed in the middle of a cast ingot to cool the center of the cast ingot, and accordingly, the quality of the center of the cast ingot is improved remarkably.