When replacing fixed cone liner, we minght be unable to take it away because the liner and cone connecting too tight. We can solve the trouble by gas cutting, and then clean the fixed cone inner surface. The concrete on the back of liner board is consist of NO.500~NO.600 cement and sand, which is in proportion to 1:3. The liner board must be grinded clean before casting, so that concrete can mortise with it. Once casting finished, it can be in use until the concrete fully dried.

Before replacing moving cone liner, we should at first lossen the tight nut about 15~20mm, and then start crusher for running on-load for a little period. At the same time, there should be feeded ore evenly and proffessional operator observing the running condition. Once the connected zinc alloy layer between moving cone and liner board destroied, the liner board is easy to remove. If that method can not work, we can try gas cutting. However, the cone must not be damaged. Carry old liner board down, polish moving cone clean, and then install the new one from top to bottom. And then, adjust and keep the gap between liner and cone 1-2mm by adjusting ring under cone. After installated the top liner, we should tighten and press the nut properly, then cast zinc alloy. We should pay attention that the liner and cone must be preheated before casting, and control the temperature between 150 and 200 degree. Using asbestos and clay to block the liners connected gaps to prevent zinc alloy leakage. Should the casting quality were not good, the moving cone liner would lossen at an earlier time. That needs recasting. 

How to guarantee the casting quality? There are a few measures available: 1. Based on the content of zinc alloy, we should know the smelting temperature and casting temperature. 

2. We should choose a sunny day, the cleaning, check and casting work are advised to be done successively without stop. Because rainy day is humidity. When mixed with water, the liquid state zinc alloy is easy to crack and spatter, which is likely to hurt people. And it also effects casting quality. 

3. Liner preheating had better to use charcoal instead of coke. Because firepower of coke is fierce, and the temperature increases too fast, which will lead to liner explosion. 

4. Adding zinc chloride as flux and degassing agent. Liquid zinc alloy gives out of the volatile toxic chlorine gas, there is a severe irritant, so the operation should wear protective masks. 

5. Gold casting is completed, preheating equipment under the liner should not immediately take away, let it turn off as it goes. So lining is slowly cooled, so that liner and zinc alloy and the vertebral body combined with more solid.