48results about How to "Improve grade rate" patented technology

The invention belongs to the technical field of polyamide materials, and provides polyamide 56 pre-oriented yarn and textured yarn with low boiling water shrinkage rates and preparation methods and application of the polyamide 56 pre-oriented yarn and textured yarn. The production raw materials of a polyamide 56 fiber comprise 1,5-pentamethylene diamine and adipic acid; or polyamide resin 56 is obtained through polymerization by taking 1,5-pentamethylene diamine and the adipic acid as monomers; wherein the boiling water shrinkage rate of the polyamide 56 fiber is below 9%, and the polyamide 56fiber comprises the polyamide 56 pre-oriented yarn with the low boiling water shrinkage rate and the polyamide 56 textured yarn with the low boiling water shrinkage rate. The polyamide 56 fiber has relatively good mechanical properties, dyeing uniformity and dimensional stability, and the preparation method of the polyamide 56 fiber does not need to modify existing polyamide fiber elasticizing equipment, so that the production cost is reduced.

This invention is a method of sanitary high-absorption chrome tanning. Its character is using treated waste water releasing from tannery instead of tap water and well water in the whole process. In the prophase, tanning cutting technique is utilized. In the acid soaking process, it is treated with amino resin tanning agent.

The invention provides a treatment method of standard exceeding of content of chlorine in titanium sponge. The titanium sponge is titanium sponge produced by adopting a magnesiothermic reduction method. The treatment method comprises the following steps: placing the titanium sponge in a reactor, vacuumizing the reactor until the vacuum degree in the reactor is not more than 100Pa; heating the reactor to ensure that the titanium sponge in the reactor is firstly subjected to low-temperature degassing of a temperature phase of 150-200 DEG C and intermediate temperature degassing of four constant temperature phases of 200-300 DEG C, 350-400 DEG C, 450-500 DEG C and 500-550 DEG C to remove water and gas impurities in magnesium chloride hydrate in the titanium sponge; and after degassing is ended, continuously raising the temperature to 900-1020 DEG C for vacuum distillation to remove magnesium chloride in the titanium sponge. According to the method, the content of chlorine in the titanium sponge, which exceeds the standard, can be effectively reduced, and the grade rate of the titanium sponge is increased.

The invention relates to a cleaning method for a metal chromium piece. The cleaning method comprises the following steps: producing a metal chromium piece by virtue of an electrolytic method, stripingthe metal chromium piece from a cathode plate, detecting the lead content of the metal chromium piece, directly putting the metal chromium piece into a water circulating type roller cleaning machinewhen the lead content of the metal chromium piece is less than or equal to 0.002%, cleaning by virtue of a clean water roller, adding a proper amount of nitric acid or oxalic acid into clean water inthe cleaning process when the lead content in the metal chromium piece is more than or equal to 0.002%, and cleaning; and controlling the water temperature at 30-80 DEG C in the cleaning process of the water circulating type roller cleaning machine, carrying out automatic water washing in an automatic cleaning slot by virtue of a full-automatic ultrasonic cleaning machine through clean water, controlling the ultrasonic frequency at 50Hz, then putting the metal chromium piece into a washing slot, carrying out water washing with clean water, finally putting the metal chromium piece into drying equipment, drying, and carrying out packaging. The cleaning method has the advantages that a cleaning process is simple, the operation is easy, the operational environment of workers is improved, the operational difficulty is reduced, the grade ratio of a metal chromium piece product is increased, and the energy conservation, the energy conservation and the environmental protection are realized.

The invention discloses a method for producing low carbon manganese-silicon alloy through external refining by adopting a two-step method. The method comprises the following steps: adopting a submerged arc furnace of 25500 KVA or above to produce a silicon manganese alloy product containing 22-24% of silicon; loading the silicon manganese alloy product containing 22-24% of silicon into a 20-ton intermediate frequency furnace, adding silicon iron of which the weight is 5%-15% that of the silicon manganese alloy product in the intermediate frequency furnace, electrifying the intermediate frequency furnace for smelting for 5-15 minutes, adding a slagging element of which the weight is 2.4% that of the silicon manganese alloy product and a covering agent of which the weight is 0.8% that of the silicon manganese alloy product for refining for 15-25 minutes after the temperature reaches 1400 degrees or above, cutting off the power after the completion of refining, and leaving to stand for 5 minutes; and slagging off, tapping and pouring, so as to finally obtain the low carbon manganese-silicon alloy in which the content of Si is higher than or equal to 27% and the content of C is lower than or equal to 0.2%. According to the method for producing low carbon manganese-silicon alloy through external refining by adopting the two-step method, the production scale is large, the product quality is stable, the operation is stable, the production cost is low, the cost is reduced by RMB 461 per ton, and the product grade ratio reaches 95% or above.