A rod mill uses steel rods as the grinding media in tumbling mills is an efficient means to feed ball mills a product finer than could be made in a crusher but coarser than could be made in a ball mill. The principal use for rod mills, which were invented to make ball mill feed in a wet-grinding rod mill-ball mill circuit.
Rod mills came into use in the United States beginning in 1900s and eventually became recognized as efficient fine crushers. The 1st ever built rod mill (2 m in diameter by 4 m long) was to be installed at a mine where a coarser feed was required for shaking tables. Crushing rolls and rod mills were eventually used commonly to prepare feed to shaking tables. Later, rod mills of 2.9 m in diameter by 3.9 m long replaced most roll crushers.
With the increase in the diameter of rod mills, problems occurred in the shorter rod mills with rods tangling. When the rods were short relative to the diameter, some were lifted toward a vertical position, and continued tumbling caused tangling. This led to the arbitrary rule that the length of rods should be at least 1.5 times the mill diameter inside new shell liners.
The crushing action of the rod mass in a rod mill has been described and is illustrated in diagrams taken from his work in Figure 1. The progressive sizing of material from the feed to the discharge end of the mill by the tapered slot openings between the rods, and the resulting effective internal classification has been widely observed and documented. Apparently, the rod mass acts as an effective screen, holding back coarse particles from progressing along the length of the mill until crushed fine enough to pass along the slots. As well, the coarser particles tend to take the brunt of the rod impacts, and hold the rods apart, preventing the finer particles from being overground. These basic mechanisms ore consistently observable in the size distributions of rod mill products despite a multitude of other complex interactions taking place in the elevated charge, in the slurry pool, and due to the nature of the ore, slurry rheology, and mill design and operating variables. The historical trend towards producing a coarser rod mill discharge (equivalent to a higher feed rate per unit of mill power draw or volume) parallels the recognition of its natural preference to perform work on coarse material.
Energy efficiency in grinding is directly related to circuit economic performance because of the close interdependence of energy and media consumption, and their combined dominance of total direct grinding costs. Energy usage itself is the prime criterion by which grinding circuit process performance can be technically evaluated using the Bond Operating Work Index. As well, a knowledge of the possible range and nature of individual equipment energy consumption is required to determine the scope of possible changes in the process performance characteristics of each comminution stage. The following discussion therefore focuses on the effects of design or operating variables on both power draw and power efficiency, as well as giving consideration to some practical constraints for operating ease and stability.
The main metal elements of lead-zinc ore are lead and zinc. Due to the high utilization value of lead and zinc, they are widely used in electric, mechanical, metallurgical, chemical and other industrial fields. FTM lead-zinc rod mill is developed according to the nature of the lead-zinc mine, it is a new efficient rod mill equipment with high use value and the affordable price, so that it can meet the price requirements of customers who have just joined lead-zinc mine industry. Here we mainly offer our introduction about some relevant knowledge of FTM lead-zinc rod mill.
2.The lead-zinc rod mill adopts advanced rod mill technology, it is configured the appropriate grinding medium combined with the lead-zinc ore material, to make the discharging granularity of material more uniform and improve the production of lead-zinc mine.
3.By simple adjustment of the lead-zinc mine rod mill, the finished grain size of the discharge port can be changed, and its interior has a special device for adjusting the material fineness, so as to ensure that the material is not over-grinding.
1.Lead-zinc rod mill is widely used in the gravity separation and magnetic separation of the rare metal ore, in order to prevent the adverse effects of material over-grinding, so at this circumstance the rod mill is often used in the production line.
2.When we need a two-stage grinding process to finish the material grinding, we can use the available rod mill as the first stage grinding equipment to effectively improve the production efficiency, but when we need the fine grinding equipment in both grinding processes, its production efficiency is much lower than other equipment, so it is not suitable in this situation.
3.In some cases, the rod mill can be used in fine-grinding operation instead of the short head cone crusher. When dealing with the not too hard ores or soft ores, the rod mill compared with the short-head cone crusher, its configuration is simpler, cost is lower, and the dust removal effect is better. But for those hard ores, the short-head cone crusher may be more appropriate than the rod mill.
Fote Machinery is a professional manufacturer of lead-zinc mine rod mill. We have the large equipment production plant and facilities, have our own professional technical group and sales group, meanwhile, we have the certain experience of the lead-zinc rod mill production.
The quality of lead-zinc rod mill is guaranteed. All of our equipment must go through layer upon layer inspection, and we also equip with professional quality inspection personnel for the equipment quality detection. The equipment that meet the quality requirements can be sold, not only is the quality good but the price of the equipment is also very cheap, the price is set in the range that the consumer can accept.
After-sales service level is high. We have professional and technical personnel to recommend the right equipment for the customer, we also equipped with after-sales service personnel for equipment installation and debugging, offer free operating knowledge training for the equipment operation personnel and inform them the maintenance process and other considerations. In addition, if you have the problem of equipment, you can also call our free telephone for consultation, and there will be professional people to answer for you.
Our automatic production line for the grinding cylpebs is the unique. With stable quality, high production efficiency, high hardness, wear-resistant, the volumetric hardness of the grinding cylpebs is between 60-63HRC,the breakage is less than 0.5%. The organization of the grinding cylpebs is compact, the hardness is constant from the inner to the surface. Now has extensively used in the cement industry, the wear rate is about 30g-60g per Ton cement.
Grinding Cylpebs are made from low-alloy chilled cast iron. The molten metal leaves the furnace at approximately 1500 C and is transferred to a continuous casting machine where the selected size Cylpebs are created; by changing the moulds the full range of cylindrical media can be manufactured via one simple process. The Cylpebs are demoulded while still red hot and placed in a cooling section for several hours to relieve internal stress. Solidification takes place in seconds and is formed from the external surface inward to the centre of the media. It has been claimed that this manufacturing process contributes to the cost effectiveness of the media, by being more efficient and requiring less energy than the conventional forging method.
Because of their cylindrical geometry, Cylpebs have greater surface area and higher bulk density compared with balls of similar mass and size. Cylpebs of equal diameter and length have 14.5% greater surface area than balls of the same mass, and 9% higher bulk density than steel balls, or 12% higher than cast balls. As a result, for a given charge volume, about 25% more grinding media surface area is available for size reduction when charged with Cylpebs, but the mill would also draw more power.