33results about How to "Reasonable gradation" patented technology

The invention discloses a high-temperature-resistant energy-saving silicon carbide plate and a preparation method thereof, belonging to the technical field of ceramic materials. The high-temperature-resistant energy-saving silicon carbide plate is prepared from the following components in percentage by weight: 20-40% of 3.0-1.0mm SiC particle, 10-205 of 1.0-0.5mm SiC particle, 5-15% of 0.5-0.088mm SiC particle, 15-25% of 0.088-0.003mm SiC fine powder, 5-10% of 0.003-0mm SiC micropowder, 5-10% of 0.088-0mm silicon micropowder, 1-5% of composite binder, 0.5-1.0% of composite antioxidant and 1-7% of water. The preparation method comprises the following steps: proportionally mixing the materials, forming, drying, firing, and spraying a high-temperature oxidation-resistant paint on the surface. The high-temperature-resistant silicon carbide plate has the advantages of high density, high compressive strength and folding strength, consumption reduction, energy saving, lower waste gas emission and waste reutilization.

The invention discloses a preparation method of normal pressure-sintered silicon carbide ceramics, which adopts a solid normal pressure sintering method and takes submicro silicon carbide powder, graphite powder and boron carbide powder as main materials. The method comprises the following steps: 1) material grinding is carried out by adopting a staged ball milling mode, firstly, the main raw materials are ball-milled by adding water under the environment of the pH value being 10-12 to lead the agglomerated silicon carbide micro powder and other main raw materials to be evenly dispersed; thena plasticiser, a lubricant and water soluble phenol resin are added and ball-milled for a period of time; and finally a caking agent is added for ball milling; 2) spray granulation technology is adopted for carrying out granulation on the silicon carbide slurry; (3) the materials after granulation are maintained under constant temperature and humidity; (4) double-sided compression moulding is carried out on the maintained materials; (5) a staged drying mechanism is adopted for drying the molded body; and (6) the silicon carbide body is put in a vacuum firing furnace for being subjected to twotimes of sintering by taking the argon as protective gas. The silicon carbide ceramics prepared by the method have superior performance, corrosion resistance and long service life, and are applicableto commercial process.

A preparation method of high-performance recycled aggregate concrete is characterized in that waste concrete is broken to obtain large stones with granularity of 20 to 25mm, small stones with granularity of 5 to 20mm and sand with granularity of smaller than 5mm, and dust produced in the breaking process is pneumatically collected; and then the large stones, the small stones and sand are mixed with polycarboxylic acid water reducing agent, cement and appropriate water to further obtain the high-performance recycled aggregate concrete. Against for the special situation of the waste concrete, the waste concrete is smashed and screened on purpose, so that a new concept for treating the waste concrete is provided, the problems such as worsening of engineering disasters, resource waste and environmental pollution can be avoided, and the performance of the recycled concrete is excellent.

The invention relates to a method used for producing yellow phosphorus from low-grade phosphate ore. According to the method, phosphate ore powder with appropriate silicon content and low iron content is obtained via selectively adapting silicon concentrating or removing technology and removing iron-containing compounds in smashing period based on the difference of phosphate ores in mining period; a first time P2O5 enrichment and a second time P2O5 enrichment are carried out respectively via drying, roasting, or obverse flotation, or reverse flotation, drying,, curing, and obtaining of phosphate ore balls. The method is low in cost, high in efficiency, is friendly to the environment, is capable of improving yellow phosphorus quality, avoiding accidents or faults such as arch structure formation, material collapse, and electrode broken, and ensuring safe, stable, and high efficiency operation of electric furnaces.

The invention relates to a low-temperature fast-fired environmentally-friendly pottery clay plate prepared from iron ore tailings and a preparation method thereof. Iron ore tailings obtained by iron ore enterprise production is used as a main solvent raw material and is adopted by a formula of the low-temperature fast-fired environmentally-friendly pottery clay plate. The low-temperature fast-fired environmentally-friendly pottery clay plate comprises a superfine plastic material, a fine lean material, fine iron ore tailings, a coarse lean material, a plasticizer and water. The formula of the low-temperature fast-fired environmentally-friendly pottery clay plate comprises illite, kaolin, chinastone, pyrophyllite, iron ore tailings, the coarse lean material, the plasticizer and water. The preparation method comprises the following steps of uniformly mixing 15 to 35% by mass of the superfine plastic material, 10 to 45% by mass of the fine lean material and the coarse lean material, 20 to 50% by mass of iron ore tailings and 0 to 5% of by mass of the plasticizer, adding 10 to 28% by mass of water into the mixture, carrying out extrusion molding by a screw-type extruder, drying, and carrying out sintering in a roller kiln having the length of 280 meters at a temperature of 1000 to 1100 DEG C, wherein a sintering period is in a range of 1 to 1.5 hours. The mixed raw materials adopted by the preparation method have good extrusion performances and good drying and sintering performances. The low-temperature fast-fired environmentally-friendly pottery clay plate sintered by the preparation method has high strength and small contractility, cracks and deforms difficultly, can be sintered fast and has high environmental protection benefits and economic benefits.

The present invention relates to a cold aggregate batching treatment method for continuous-stirring equipment of bituminous concrete for highroad surface construction and asphalt parement regeneration engineering, and is characterized by that before the cold aggregate is continuously metered, firstly, said cold aggregate is passed through sieving machine to implement pregradation, then continuously metered by means of metering device then fed into continuous bituminous concrete stirring equipment and its next stoving procedure.

The invention belongs to the technical field of cement grinding, in particular to a semi-finished pre-grinding vertical-milling and ball-milling combined grinding device which comprises a semi-finished pre-grinding vertical-milling machine and a ball milling machine, wherein the feeding end of the semi-finished pre-grinding vertical-milling machine is connected with the discharging end of a proportioning belt scale, a gas outlet is connected with a dust remover, and the discharging hole of the dust remover is connected with a finished product conveying machine; the discharging hole of the semi-finished pre-grinding vertical-milling machine is connected with a lifting machine through a vertical milling discharging belt, and the discharging hole of the lifting machine is connected with the feeding hole of the ball milling machine; the gas outlet of the ball milling machine is connected with the dust remover, the discharging hole of the dust remover is connected with the finished productconveying machine; and the discharging hole of the ball milling machine is connected with a powder concentrating machine through the lifting machine, the finished product fine powder discharging holeof the powder concentrating machine is connected with a third finished product conveying machine, and the crude powder discharging hole of the powder concentrating machine is connected with the feeding hole of the ball milling machine through a feed back conveying machine. The invention combines high yield and energy saving of the vertical milling machine with cement grading advantages of the ball milling machine, and has lower investment, lower electricity consumption, more reasonable grading of cement particles, very convenient maintenance and remarkable economic benefit.

The invention relates to the technical field of building materials, in particular to a self-made low-defect ultra-high-strength lightweight aggregate, which is made of the following raw materials in parts by weight: 700-770 parts of cement, 90-110 parts of fly ash, and 210-230 parts of silica fume 90-135 parts of hollow glass beads, 4-8 parts of polyvinyl alcohol fiber, 360-520 parts of quartz sand, 1.8-2.2 parts of active activator, 28-35 parts of water reducing agent, 0.06-0.08 parts of defoamer , 135-155 parts of water; the self-made low-defect ultra-high-strength lightweight aggregate adopting the technical solution of the present invention has very obvious advantages when preparing lightweight high-strength concrete, and has broken through the strength bottleneck of lightweight concrete represented by ceramsite concrete , and at the same time solve the problem of poor coordination between aggregate and matrix in concrete, with good feasibility and broad application prospects.

The method provides a method for constructing artificial wetland through aged refuse for processing sewage, which includes the following steps: extracting, airing, sieving and sorting the aged refuse to obtain granular loose fine material; constructing an artificial wetland substrate bed by taking the aged refuge fine material as the base substrate together with other substrates; and growing hygrophytes on the bed. The method not only provides a new option for substrate for processing various types of sewage through wetlands and provides an approach for improving the additional value of the aged refuge.

The invention belongs to the field of ceramic processes, and in particular relates to a process for preparing a microcrystal wear-resisting alumina ceramic. The process comprises the following steps: ball-milling raw materials into small particles of 1.8 micrometers; detecting the particle size of slurry; drying and milling the slurry, and then grading the particles; performing pressure forming on blanks; and finally sintering the ceramics. The process has the following advantages: in the process of milling, a servo system is used when conveying the materials from a stock tank to a spray drying tower to ensure that the flowing slurry is even and the moisture in the prepared powder is even; and the adoption of mesh screens with different diameters to perform particle gradation is more reasonable and the particle distribution is controlled precisely.