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Carmeuse North America crushes over 14 million tons per year of limestone and dolomite for the production of lime in North America. The cost of crushing the stone is the single largest consumer of energy in a stone preparation plant and the crusher typically represent the single largest capital equipment cost in the stone processing plant. Crushing of stone is required to provide properly sized stone for use in kiln operations. The crushing operation and the screening operation do not add value to the value of the stone. The crushing and screening operations are costs to an operation. In lean manufacturing terms, crushing and screening provide no Dry grind processing added value. There are two key operating functions of a crushing operation. The first is to maximize the production rate through the crusher and the second is to maximize the percentage of properly sized stone produced by the crusher.

The crusher typically controls the production rate in a mineral processing operation. This is because the capital cost, installation cost and operating cost of crushers are the single largest cost in a crushing operation. The crusher is typically the unit upon which the stone processing plant is designed around. Thus the crusher is typically the system bottleneck. A typical stone crushing operation for a lime operation includes a primary and a secondary crusher. A common primary crusher installation consists of a jaw crusher equipped with a grizzly feeder to bypass fines. Secondary crushing normally consists of a cone type crusher in closed loop with a screening system. The throughput capacity of crushers is most related to the physical size of the machine. Increasing the physical size of the machine also increases the maximum size of the material the crusher can process. The reduction ratio also affects the production rate. Running a crusher faster or at a higher rpm is not a viable option to increase throughput.

The second item of importance to a crushing operation is the maximization of the percentage of properly sized stone for use in the calcining operation. This is defined as the yield of the crushing operation. Yield is the percentage of the total amount of stone Coal preparation plants processed that is properly sized and available for calcining. The ideal situation is to maximize the yield at the maximum throughput rate of the crushing operation. This ideal situation is rarely obtainable and a compromise must be achieved that will allow the production of properly sized stone within an acceptable time frame. However all three of these options involve the expenditure of large sums of money. Most operations have a limited supply of money so other options to increase capacity must be evaluated. The following are options that can be implemented to increase the capacity of a typical primary and secondary crusher system.  The options listed above for the primary crusher reduce the reduction ratio of the grinding mills for taconite ore crusher because opening up or increasing the settings bypasses more of the limestone. This places a greater burden on the secondary crusher. This relationship is shown on the attached graphic. With its high quality products such as hammer crusher, Hongxing Machinery has ascended in the front rank of the world in the exporting of mining equipment.