3results about How to "Full reduction reaction" patented technology

The present invention discloses quartz pellets for silicon alloy production, wherein the quartz pellets contain SiO₂>96%, Al₂O₃<0.8%, and Fe₂O₃<0.8% by weight. The quartz pellets are approximately spherical in shape. When used for silicon alloy production, the quartz pellets and the carbonaceous reducing agent fall freely from the material tube and enter the surface of the ore-fired furnace. The large balls are quartz pellets, and the small balls are carbonaceous reducing agent pellets. The large and small balls are tightly packed and evenly distributed. When the furnace temperature is below 1700°C, no deflagration or explosion will occur. The quartz pellets have the characteristics of high reducibility, high explosion resistance, high specific surface area, high porosity in the pellets, low reduction starting temperature, energy saving and environmental protection, etc. The reducing atmosphere is good, and a large amount of reducing gas will enter the internal pores of the pellets to carry out microcirculation reaction, without stab fire phenomenon, and high heat energy conduction efficiency.

The invention discloses ultra-coarse tungsten carbide and a preparation method thereof, and the preparation method comprises the following steps: providing ultra-coarse tungsten oxide particles with the water content of 3-5 wt%, the average particle size of the ultra-coarse tungsten oxide particles being 28-45 [mu] m; loading the ultra-coarse tungsten oxide particles into a boat, placing the boat in a closed reduction furnace, introducing hydrogen, and carrying out a reduction reaction to obtain ultra-coarse tungsten particles; wherein the temperature of the reduction reaction ranges from 950 DEG C to 1100 DEG C, the boat loading amount ranges from 2.8 Kg / boat to 3.5 Kg / boat, the circulation time ranges from 45 min / boat to 60 min / boat, the hydrogen flow ranges from 8 m < 3 > / h to 15 m < 3 > / h, and the hydrogen dew point ranges from-65 DEG C to-75 DEG C; the ultra-coarse tungsten particles and carbon are mixed, and a carbon mixed material is obtained; performing high-temperature carbonization on the carbon-containing mixture to obtain tungsten carbide particles; the tungsten carbide particles are crushed and sieved, the ultra-coarse tungsten carbide is obtained, and the average particle size of the ultra-coarse tungsten carbide ranges from 30 micrometers to 60 micrometers. According to the method, the ultra-coarse tungsten particles with high purity and more uniform particle size distribution can be obtained.

The application discloses a preparation method of 3-chloro-5-fluoro-2-methylbenzoic acid, relates to the technical field of 3-chloro-5-fluoro-2-methylbenzoic acid production, and the method is characterized in that: 2-methyl-5-nitrobenzoic acid is used as a starting raw material, selective chlorination is carried out on the starting raw material in preheated high-temperature concentrated sulfuric acid and dichloro hydantoin, then esterification is completed by a one-pot method, catalytic hydrogenation reduction is carried out under low-pressure and low-temperature conditions by the synergistic action of a Raney nickel catalyst and a platinum-carbon catalyst, a high-purity amino intermediate is obtained, smooth thermal decomposition fluorination is carried out in a diglycol dimethyl ether solvent, alkaline hydrolysis and refinement are carried out, and finally the end product is obtained; the product has high purity and high yield.