Abstract: The invention relates to a noxious gas purificant and its preparation and purification method for removing nitrogen oxides from gas streams thereof. The preparing method is characterized in that: mixing, according to a predetermined ratio and a process, a salt of iron, manganese, cobalt, or copper, and a related derivative thereof, an alkali or alkaline substance and a related derivative thereof, water and a forming agent, so as to obtain a solid compound or mixture; drying and activating the solid compound or mixture to produce a solid product as the purificant; and introducing the purificant into a gas-solid reactor, and removing noxious gases in a gas stream by performing, in a preconfigured temperature and using the purificant, a gas-solid reaction on the harmful gases in the gas stream. The purificant can be recycled and reused.

Abstract: Disclosed is a method for grinding a spring with high quality and high efficiency, comprising the steps as follows: firstly, at least one of an upper grinding wheel (1) and a lower grinding wheel (2) is configured to comprise an inner grinding wheel (21) and an outer grinding wheel (24), wherein the inner grinding wheel (21) is fitted in the outer grinding wheel (24); the inner grinding wheel (21) or the outer grinding wheel (24) is driven by a transmission mechanism, the inner grinding wheel (21) and the outer grinding wheel (24) rotating in opposite directions; after a complete spring is fed to a space between the upper grinding wheel (1) and the lower grinding wheel (2), the complete spring is moved back and forth in the plane of the grinding wheels; and then the upper grinding wheel (1) is moved downwardly such that two end faces of the spring are ground by the grinding wheels, and when the height of the ground spring meets the requirement, the upper grinding wheel (1) is stopped moving downwardly and is

Abstract: Disclosed is a method for grinding a spring with high quality and high efficiency, comprising the steps as follows: firstly, at least one of an upper grinding wheel (1) and a lower grinding wheel (2) is configured to comprise an inner grinding wheel (21) and an outer grinding wheel (24), wherein the inner grinding wheel (21) is fitted in the outer grinding wheel (24); the inner grinding wheel (21) or the outer grinding wheel (24) is driven by a transmission mechanism, the inner grinding wheel (21) and the outer grinding wheel (24) rotating in opposite directions; after a complete spring is fed to a space between the upper grinding wheel (1) and the lower grinding wheel (2), the complete spring is moved back and forth in the plane of the grinding wheels; and then the upper grinding wheel (1) is moved downwardly such that two end faces of the spring are ground by the grinding wheels, and when the height of the ground spring meets the requirement, the upper grinding wheel (1) is stopped moving downwardly and is