Inspection Of Zinc Ingots

Zinc ingot supplier to share with you: according to the production method, Classification of zinc ingot

(1) Electro-galvanized—Zinc produced by electrolytic process, the highest purity;

(2) Smelting zinc—refined by zinc ore and other steaming methods, followed by purity;

(3) Recycled zinc—also called remelted zinc, which is made by smelting waste zinc twice or more, with more impurities

1 Sampling and preparation:

Select a few in a batch of zinc anodes, drill zinc scraps at different locations, mix the zinc scraps, use a coarse balance to weigh three 1g samples and place them in 300ml conical flasks, each adding 1: 1 10 ml of hydrochloric acid, 3 to 5 drops of hydrogen peroxide, heat to dissolve, and boil for 2 min to remove excess hydrogen peroxide.

2 Qualitative test

2.1 Characterization of iron impurities:

Take a test solution, neutralize it with 20% sodium hydroxide to weak acidity (pH 3-4), add 1 tsp of potassium thiocyanate (or ammonium thiocyanate), and shake well.

If it contains iron impurities, the iron-forming thiocyanate complex is red. If the test shows blood red, and the color is darker, it indicates that the anode is impure. Red indicates that there are very few iron-containing impurities in the zinc anode, and the anode can be used.

 Zinc Ingot China

2.2 Characterization of copper impurities:

Take a portion of the test solution and neutralize it with concentrated ammonia water until the ammonia smell (the solution is alkaline). If it contains copper impurities, copper-ammonia complex ions will be generated and appear blue. If the test is colorless or light blue, it indicates that a trace amount of copper is contained, and the zinc anode is still usable; if the test is dark blue, there are many copper impurities and the anode cannot be used.

2.3 Characterization of lead impurities:

Take a test solution, neutralize it with 20% sodium hydroxide until the white zinc cyanide oxide precipitates, add 20% sodium cyanide solution until the precipitate dissolves, and excess 3 ~ 5ml, add a small spoonful of reagent grade sodium sulfide , Shake well. With lead impurities, black lead sulfide precipitates are formed (such as copper was identified earlier, and the black precipitate also includes copper sulfide). The test is light gray, with a small amount of surface impurities, and the zinc anode is available; when the test is dark gray to black, it cannot be used (the white precipitate in the test solution is zinc sulfide).

In short, no matter which impurity is qualitatively identified, the entire batch of zinc anodes cannot be used.

In short, no matter which impurity is qualitatively identified, the entire batch of zinc anodes cannot be used.

Misunderstanding of the use of recycled zinc:

In the production of zinc ingot china, many companies are happy to use recycled zinc and think it is cheap, but this is only one of the reasons. In fact, the use of recycled zinc is not entirely due to the low price. The other reason is that it contains a certain amount of zinc. Can be used as a cheap source of hot dip galvanizing and tin.

However, it should be noted that recycled zinc tends to increase the viscosity of zinc in the zinc pot, and the cost of solving this problem often exceeds the cost savings brought by its cheapness, and sometimes it pays off.