前言我厂生产的稀土镁合金,其中含镁为15～20%;稀土氧化物为25%以上;硅为30%左右;余量为铁。由于稀土元素的化学性质很相似,所以常是测其总量。稀土元素的氟化物是所有的稀土沉淀中溶解度最小的;在稀的无机酸中草酸稀土也能沉淀;稀土的氢氧化物也沉淀。镁在铵盐存在下,加氢氧化铵不会沉淀使与铁、稀土分离,然后在滤液中采取不同的方法来测定镁(如磷酸铵镁重量法;络合滴定法)。至于稀土 Preface I plant the production of rare earth magnesium alloy, which contains 15 to 20% magnesium; rare earth oxide is more than 25%; silicon is about 30%; the balance of iron. Due to the very similar chemical properties of rare earth elements, it is often measured the total amount. Rare earth element fluoride is the smallest of all rare earth precipitation solubility; rare earth acid in rare earth oxalate precipitation; rare earth hydroxide precipitation. Magnesium In the presence of ammonium salts, addition of ammonium hydroxide does not precipitate to separate iron from rare earths, and magnesium is then measured in the filtrate by different methods (eg magnesium ammonium phosphate gravimetric method; complexometric titration). As for rare earth