Study On Preparation Of Sheet Zinc Powder

Sheet zinc powder with suitable size and morphology is the most important material of zinc-chromium coating(DACRO), often prepared by ball milling or rubbing method, which is a products with high technology and high profits.Based on shattering mechanism and the corresponding models, the properties and characteristics of a variety of ball miller are analyzed and compared, the surface modified mechanism of powder is discussed, and it is put forward that sheet zinc powder is prepared by high energy ball milling.A horizontal high energy stirring ball miller is used to prepare sheet zinc powder. Under the dry ball milling conditions, milling time, temperature, rotation speed, the ratio of ball and materials, ball size and atmosphere are investigated. The corresponding conditions are agreed on as follow: ball size:3mm; rotation speed : 1300 ~ 1100 rpm; ratio of ball and material: 8: 1 ~ 12: 1; milling temperature: 42℃; milling time:50 min; inert atmosphere; particle size of raw zinc material:7 ~ 15um. On the basis of the experiments, effects of the quantities and varieties of surfactants on sheet zinc powder are investigated, and it is concluded that surfactants have obvious effects on particle size and properties of sheet zinc powders, the quantity of surfactants is 1.0% ~ 2.0%,and the composite surfactants are finally chosen. The results show that the zinc powders prepared by thistechnology are in the shape of sheet with a diameter of 20 um and diameter / thickness ratio of 50, which is the exact same with the products of German Aika company.