The dechroming mechanism of organic acid from chrome shavings was studied from the following aspects,the depolymerization of complex compound,the replacement of H+ and the replacement of organic acid radical anion.

The oxidation dechroming using hydrogen peroxide was comprehensively studied.

The effect of dechroming temperature, the offer of phosphoric acid and the reaction time on the amount of dechroming and collagen hydrolysis were studied.

It was found that Cu of CuNiCrAl alloy in low temperature H_2SO_4 solutions is easier subject to corrosion than Cr; and dechromisation of the CuNiCrAl alloy occurs at a certain concentration and temperature of H_2SO_4 solutions,and the tendency of dechromisaion of the CuNiCrAl alloy increases with increasing concentration and temperature of H_2SO_4 solutions.

2709 alkalic protease was used to hydrolyse dechromed chrome shavings, and the factors that may affect the collagen hydrolysis ratio, including the amount of 2709 alkalic protease, temperature, pH and time of hydrolyzing reaction, were studied.

Key points of smelting process,such as decarburization and Cr yield,thermal compensation,bottom blowing patterns,as well as high-efficiency desulphurization are discussed in the paper.

The cause of scraping of Cr-layer broke off from Cr-mask in cleaning was analyzed.