mineral processing technology and mineral processing equipment

Size separation is the parceling of particulate material on the basis of size. In mineral processing plants , such parceling means that the transfer of material unsuited for a specific processing step (such as the transfer of fines to a primary jaw crusher or the transfer of oversize to flotation) is avoided to improve the performance or efficiency of equipment or metallurgical processes. Devices employed for size separation may be screens (grizzlies, fixed screens, revolving screens, shaking screens, and vibrating screens ) or classifiers (nonmechanical classifiers, mechanical classifiers, cyclone classifiers, and pneumatic classifiers). Screens allow certain particles to pass through screen apertures, whereas classifiers act on particles suspended in a medium to separate them based on differences in characteristics such as particle size and specific gravity. In general, classifiers behave like imperfect screens. Mineral processing circuits employ sizing devices for various reaso

The cost of comminution operations is typically a very significant proportion of the total cost for mineral processing. Comminution costs are conveniently divided into two parts: Capital costs (the original cost of equipment and its installation) and operating costs (the day-to-day costs associated with power, wear parts, maintenance, and labor provided by operators). Typical capital costs are shown in Tables 1 and 2  for a copper ore and an iron ore processing operation, respectively. The total investment cost for the copper crushing and grinding plant is about $48.8 million. The total investment cost for the iron ore crushing and grinding plant is about $54.2 million. It should be kept in mind that the hardness of these two ore types differ by 113% and that the final product size of each is different. Copper ore product size required for flotation is about 80% passing 100 mesh, whereas the iron ore size required for making iron ore pellets is approximately 80% passing 2

To conclude the discussion on mineral processing plant control, two case studies are presented. One is taken from crushing and the other from grinding. Crushing Case Study In the new millennium crusher control applications in mineral processing will be largely restricted to primary and autogenous/semiautogenous pebble crusher applications. Nevertheless, there are still some crushing plants in operation, and from a pedagogical perspective, some interesting lessons can be learned from the control work that was performed in these types of operations. Figure1 provides the process and instrumentation layout required for the example. Because the secondary crushing circuit was proving to be a bottleneck for overall plant production, the general objective was to increase throughput.  Fig1. Secondary crusher control process and instrumentation layout A number of control problems in this circuit rendered more traditional methods ineffective, including the following: 1.  Giv

In the gravity separation process, the shaking table is the most common equipment. In many kinds of shaking table, the 6S type is the most common application. The structure of the 6S shaking table produced by Sinonine is shown as below： sinonine can also provide  sand washing plant  epc.

In mineral processing plant , although there may be elements of discrete I/O in control strategies (e.g., opening or closing cyclones to maintain header pressure), they are normally designed to continuously modulate manipulable variables (e.g., feeder speed, valve position, pump or mill speed) to ensure that the controlled variables (e.g., ore flow, water flow, tank level, particle size) are at or near the set-point value. For that reason the emphasis in this section is on continuous control, and Figure 1 conveniently summarizes the levels of continuous control, while offering insight into the structure of control strategies. Fig 1. The levels of continuous control Fig 1 illustrates that there is some performance benefit associated with each level of control strategy. It also carries the important implicit message that control strategies are hierarchical. That is, one cannot build an effective supervisory strategy if the regulatory strategies underpinning it are ineffective.

In a beneficiationplant , Process control is an essential component of any comminution system. The widespread adoption of automation in mineral processing plants began more than four decades ago, when rudimentary regulatory strategies for regulation of ore, water, and slurry were successfully deployed on single-loop analogcontrollers. Virtually all plants built today have a sophisticated digital control system that enables all basic control functions, providing the human – machine interface (HMI), and acting as the gateway to plant management information systems, which couple process and business controls. In addition, most new plants adopt advanced process control applications to deal with the multivariable nature of process optimization in real time. Although the journey has not always been smooth, the industry has increasingly embraced process control as one of the most capital-effective investments available in the pursuit of lower costs and increased revenues. The need for proc

The various mining machine including grinding devices used in the industry are distinguished in terms of the manner by which energy is introduced into the system and in terms of capacity and particle transport into and out of the mill. Each device is characterized with respect to particle size range, design relationships, wear, and efficiency of energy utilization. For some grinding devices, well-defined design relationships have not been established, and in these cases detailed data on typical installations are given when available. Similarly, wear data for some grinding devices are not always available, especially for the more recently developed mills that have not been used extensively on an industrial scale. In addition, the wear characterization is difficult to generalize because it is highly dependent both on the nature of the feed and the materials of construction. The efficiency characterization is the free-crushing efficiency and represents that portion of the total energ

In beneficiation plant , the types, sizes, and number of crushers employed in a complete reduction system will vary with such factors as the volume of ore to be processed, ore hardness, and the size of the feed and product. GyratoryCrushers . Primary crushers are heavy-duty machines run in open circuit (sometimes in conjunction with scalping screens or grizzlies). They handle dry run-of-mine feed material as large as 1 m. There are two main types of primary crushers—gyratory crushers and jaw crushers . Gyratory crushers are the most common for new operations. Secondary crushers are lighter-duty and include cone crushers, roll crushers , and impact crushers. Generally, the feed to these machines will be less than 15 cm, and secondary crushing is usually done on dry feed. Cone crushers are similar to gyratory crushers, but differ in that the shorter spindle of the cone is not suspended but is supported from below by a universal bearing. Also, the bowl does not flare as in a gyr

In practice, size reduction of mineral particle assemblies is accomplished stepwise in commercial devices. The complicating features in the breakage of large assemblies of particles are the different particle sizes and strengths and the sometimes random way in which stress is applied in the various steps. In mining operations, blasting with explosives is usually the first step in the comminution sequence. During blasting, high-velocity gas pressure pulses created by the explosives load blocks of ores to provide initial fragmentation. The next step in mineral processing plant is typically crushing, which is accomplished by slow compression of large particles (greater than 1 cm) against rigid surfaces. The mechanism of breakage in the crushing step is contrasted with subsequent size reduction by tumbling or stirred mills in which breakage of smaller particles (less than 1 cm) is accomplished by a combination of impact, chipping, and abrasion events caused by energy transferred from gri