31results about How to "Control sedimentation rate" patented technology

The invention discloses a method for producing a grinding electroplated diamond wheel. The method comprises the steps of: 1, preparing an electroplating bath; 2, pre-treating before plating; 3, pre-plating, wherein the current density is 1.2-1.8A / dm<2>, and the thickness of a pre-plating layer is 7-10micrometers; 4, magnetically sand feeding, namely applying magnetic induction intensity of 400-1000mT on a plating surface of a grinding wheel base body so as to absorb a diamond abrasive through the plating surface of the grinding wheel base body, and depositing an electroplating layer through electrifying, wherein the sand feeding current density is 0.5-0.8A / dm<2>, and the thickness of the plating layer is 15% of the average particle size of the diamond abrasive; 5, thickening, wherein the current density is 1.6-2.0A / dm<2>, and the thickness of the thickened plating layer is 65% of the average particle size of the diamond abrasive; and 6, treating after the plating so as to obtain the grinding electroplated diamond wheel. By utilizing the method for producing the grinding electroplated diamond wheel, the abrasive with fine granularity can be uniformly solidified on the plating surface, and the produced grinding wheel has good shape retention performance and satisfies grinding requirements on high precision and high efficiency.

The invention discloses a preparation method of a cerium-zirconium based solid solution. The preparation method comprises the following sequential steps: (1) preparation of Ce<4+>; (2) preparation of active ingredient solution; (3) precipitation reaction; (4) surface modification; (5) roasting. The Ce<4+> is prepared firstly and then mixed with other rare earth ions and positively quadrivalent zirconium ions to obtain a mixed metal nitrate solution; as the mixed metal nitrate solution contains an organic complexing agent, the precipitation speed in the precipitation reaction process is controlled by virtue of complexing coordination of the organic complexing agent and the rare earth and zirconium ions, so that a precursor uniform and stable in particle size is obtained; the surface treatment is performed on the precipitate precursor by use of polyacrylic acid, and therefore, the agglomeration problem of particles in the roasting process is solved, and the pore diameter and the pore volume of the roasted product are increased, and consequently, the cerium-zirconium based solid solution catalytic material excellent in heat stability is obtained. The preparation method is suitable for the preparation of the solid solutions.

The invention discloses an aluminum-doped spinel manganese-based material and a preparation method thereof. The method comprises the steps of respectively putting configured manganese source compound solution, or a nickel source compound, aluminum salt compound solution and a precipitator solution into a reactor according to the flow rate being 0.5-2L / h, stirring to control the pH value of a system to be 7-8.5 and the heating temperature of the system to be 30 DEG C-60 DEG C, heating and then curing for 10h-20h to obtain a spherical precipitate precursor, washing and drying the spherical precipitate precursor; forging the dried precipitate for 5-20h under the temperature being 600-900 DEG C; and sufficiently mixing oxidizing materials and a lithium source compound according to a proportion that the stoichiometric ratio exceeds the lithium source compound by 1-10%, and forging for 5-20h under the temperature being 600-900 DEG C to obtain the modified spinel manganese-based material. According to the method disclosed by the invention, the feature of the precursor and the distribution uniformity of an Al element can be improved effectively; due to the reasonable high forging temperature and doping proportion, the structure stability of the aluminum-doped spinel manganese-based material can be improved greatly, and the circulation performance and high-temperature and low-temperature performances of the material can be improved; and the process is simple, and the repeatability is good.