The application of rubber mill liner to roughing mill has many advantages, including corrosion resistance, wear resistance, impact resistance and good elasticity. The working environment of grinding operators is improved at higher economic effect. It is widely used in the grinding process of metallurgical ore. Sweden Skega uses rubber to replace alloy steel as lining material for wet mill. Rubber mill liner was introduced to China in 1967. Over the years, the application in ore grinding industry has made rapid progress.
Overview on Production
As an important component, rubber mill liner is involved in particle grinding, stirring grinding medium continuous impact, improving shell performance and maintaining wear. Being indispensable steel consumption in concentrator, it greatly affects the production process. Adhering to a reasonable and scientific attitude should be integrated to select the products that are consistent with the working conditions of each mill. Only in this way can the quality of technical management and production and operation be improved. In the process of continuous research and exploration, Qingdao Kosga industrial gradually selects rubber liner and manganese steel liner as mill rod in stage III fine grinding. In this paper, the trial application of rubber lining plate in II stage rough grinding is fully studied and discussed.
(1)Grinding process: the design production capacity of Qingdao kosga industrial is 1500t / D (single system), mainly using three-stage two closed-circuit grinding process (two sets of M qg3.2m × 3.1m and one set of M by2.7m × 3.6m ball mills). In order to match with the actual production, two grid type ball mills were changed into overflow type.
(2)Properties of raw ore: the raw ore of a mine is gray white hard quartz sandstone. The gangue is mainly feldspar and quartz, accounting for about 93%. Feldspar and quartz are closely bonded with the rest of the gangue. Copper ores are mainly bornite, copper blue and chalcocite. The hardness of the ore is about F = 16 ~ 20.
(3) Working parameters of two-stage rough grinding: the 3.2m × 3.1m grid type two-stage ball mill was changed to overflow type, and the filling rate of the mill was 36 ± 1% with the use of 70 × 70mm casting and forging medium. The equivalent diameter is 76 mm, the grinding concentration is 72% ~ 75%, and the mill speed rate is 87.4%. The maximum particle size of the product is 2 mm, the feed size is 5 mm and the pulp pH is 7 ~ 7.5.
Brief on rubber mill liner
Rubber mill liner is a kind of nonmetal material liner, which has the advantages of wear resistance, corrosion resistance, light weight and low noise. It is widely used in cement, mineral processing and other institutions of wet grinding machine. At present, there are about 60 countries in the world using this kind of rubber liner in various specifications and wet grinding machines. However, low hardness is still a short board.
Usage of rubber mill liner
After running well on No.1 ball mill at first, rubber liner was gradually applied to all fine mills. Considering the two important factors of rubber mill liner grinding effect and rough grinding wear, it has not been used in rough grinding. In order to match with mine operation, in the process of continuous research and analysis, the rubber mill liner is finally used effectively. The comparison test results show that compared with the III stage fine grinding, the rubber liner used in the II stage roughing mill can greatly shorten the service life. Compared with manganese steel liner and metal magnetic liner, rubber mill liner still has great advantages.
The most experimental research and analysis show that the use of magnetic liner and rubber mill liner can save 0.115/t ore liner and 0.036 yuan / T ore electricity cost. If the processing capacity of 1.2 million tons / year of raw ore is used, a total of 181,200 yuan will be saved every year.
Failure mechanism analysis
Through the application of fine mill operation and comparative study of domestic and foreign wet grinding machines, rubber mill liner has strong wear resistance and a service life of 2-3 years. But in the actual use process, the rough grinding operation life cycle is only one year. Therefore, the use process and related conditions were analyzed and studied in depth, while the failure mechanism was found in the following aspects: (1) plough failure. Materials with irregular shape and multi edges are broken. The fine grinding medium which is impacted by the medium slides along the liner. Micro cutting and furrow will cause wear and rapid failure of the liner. (2) Stab failure. There is no complete iron removal from the ore. There are many sharp and tough fine steel wires in the feed ore, which are put into the liner plate after the rod mill crusher acts. Honeycomb shaped holes will accelerate the failure rate of liner.
First, rubber mill liner has the advantages of corrosion resistance, corrosion resistance and wear resistance. In the mine production activities, it contains very considerable promotion and application value. Second, rubber mill liner plays a very important role in the process of fine grinding. However, in the face of high hardness ore, ploughing failure will occur in the rough grinding operation dominated by impact crushing. Third, to improve the level of production, operation and management, and work together with the scientific and reasonable design of rubber mill liner appearance, can eliminate the sliding between liner and medium. After ploughing failure is eliminated, rubber mill liner can be widely used in roughing operation.