Method for preparing copper cladded iron composite powder

Abstract

A preparation method of copper-clad iron composite powder which includes procedures as follow: the alcaline etching waste liquor containing copper is added into the acid etching waste liquor, thus feed solution with pH between 2 and 4.5 is obtained and the concentration of copper between 50 and 100g / L. The reduced iron powder is washed by acid, delivered to a reaction kettle with turbine type stirring, added with water with stirring, added orderly with dispersant agent and inhibitor and evenly with feed solution containing copper with continuous stirring, making the copper completely claddingthe surface of the iron powder grain, thus copper-clad iron composite powder is obtained. Then the copper-clad iron composite powder is subject to pumping filtration, washing, centrifugal dehydration,antioxidation treatment, vacuum drying and screen separation, thus termination production is obtained. The method of the invention can make the copper evenly, tightly, firmly and completely claddingthe iron powder grain, and not be oxidized for six months of storage, thus increasing the oxidation resistance. The prepared copper-clad iron powder by the invention has bright surface colour and lustre, high cladding rate, even and compact surface cladding, futhermore, the cost is lower compared with prior preparation methods because of avoiding using copper sulfate.

Description

【Technical field】 [0001] The invention relates to a method for preparing metal powder required for producing oil-impregnated bearings, in particular to a method for preparing copper-clad iron-based composite metal powder by directly utilizing etching waste liquid in the printed circuit board industry. 【Background technique】 [0002] Compared with traditional ball bearings, oil-impregnated bearings have the advantages of low cost and simplified structure. With the gradual expansion of the application scope of powder metallurgy, the use of oil-impregnated bearings, one of the main applications of powder metallurgy, has become more and more widely used. By 1999, the total output of oil-impregnated bearings in my country had reached 2.5 billion. Therefore, metal powder, the raw material required for the production of oil-impregnated bearings, has also increased rapidly, and the variety of metal powder has gradually developed from mixed powder, alloy powder to composite powder. ...

AI Technical Summary

Problems solved by technology

[0003] The existing production method of copper-clad iron composite powder adopts the diffusion method, which is to mix copper powder and reduced iron powder evenly in a certain proportion, and then heat to a certain temperature to melt the copper powder and coat it on the iron powder. Particle surface, since this method is a physical method to coat copper on the surface of iron powder particles, it has the following disadvantages: 1. Because the density of copper powder and iron powder is different, segregation is easy to occur when mixing, resulting in Copper is unevenly distributed. Therefore, when copper coats iron powder particles, it is easy to produce uneven copper-coated iron powder, incomplete coating or even no coating at all, resulting in uneven appearance and color of the product, which is easy to oxidize. Too much noise due to excessive starting current

2. Because the contact between copper and iron is not tight, it is easy to wrap the gas in it, causing the copper film to bubble and fall off

Using etching waste liquid to produce copper sulfate and copper sulfate and then use it to manufacture copper-clad iron composite powder. Although the process is feasible, it has the defects of long process, complicated process and high manufacturing cost.