A New Paradigm in Sulphide Processing

By classifying flotation feed at a point where coarse recovery deteriorates, the existing flotation circuit can be optimized to improve performance

It has long been established that copper sulphide processing follows a logical progression — crush, grind, float, regrind and refloat to produce a final copper concentrate. The justification for this approach is well-based as conventional flotation technology has a defined particle size range over which it can effectively recover floatable particles. Work by numerous experts has shown that currently available flotation technology is effective over a size range of approximately 15 to 150 microns. An example of these findings is shown in the well-recognized “elephant curve” (Figure 1). Particles outside this critical size range are typically lost in industrial operations and rejected to tailings streams due to inherent constraints associated with the physical interactions that occur in the pulp and froth phases of conventional flotation equipment.

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Modern Underground Blasting Methods

What face round would work best and why?

Underground mining and construction projects face several challenges unique to the underground environment compared to the surface environment. The goals are the development of an effective blast pattern that minimizes cost, maximizes face advance, and provides the desired fragmentation and face profile. In addition to these goals, mines must consider the very real operational problems that occur, such as drill deviation, ground vibration, and deadpressing1 or sympathetic detonation2 of explosives. These operation problems lead to increased costs and decreased production in the mine, hurting the bottom line.

Combined with these problems, underground blasts can be difficult to monitor and evaluate due to tight spaces, dust during the blast preventing video, and the need to evacuate the immediate area with no clear line of sight to observe performance. This creates an environment in which most mines know that blasting can be improved in their underground operations, yet most are hesitant to change due to fears of the shot freezing, misfires and questions about how to achieve a proper design. Unlike with surface blasting, the explosives companies, and shot service providers also offer limited assistance or knowledge in the underground blasting realm, leaving underground operations in the dark. It is for these reasons that most underground operations are operating decades behind the current technologies and incurring significant costs, both real and hidden, from their blasting operations.

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Keeping Crushers at Work

In most mines, crushing provides the gateway to mineral recovery, and proper maintenance is the key to reliable crusher operation

Located at the front end of any mineral-processing system, crushers are heavy-duty, high-cost pieces of equipment of which a lot is expected in terms of throughput and reliability. If the primary crusher goes down, the chances are there will be no backup unit to take over. The plant runs through its fine ore stock, and then stops. For this reason, if for no other, properly scheduled maintenance is vital to ensuring crusher reliability, with the world’s crusher manufacturers having invested a great deal in recent years in devising technologies that help make crusher maintenance simpler and safer. As with any piece of equipment, lubrication is one of the most importance aspects of machine maintenance. Any failure of the lubrication system can have catastrophic consequences, very quickly, as bearings and other rotating parts begin to wear, then break down or seize. In addition, damage to the wear surfaces within the crusher chamber can rapidly lead to cracking and even disintegration unless appropriate remedial work is undertaken urgently. Hence, careful inspection must be a key part of any maintenance program, as well as ensuring that lubricant levels are correct and that the lubricants themselves meet the crusher manufacturer’s specifications.

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Leach Operators Get a Lift from Tech Improvements

The pursuit of higher metal recovery enters the digital age — where even time-tested, conventional leach-optimization techniques stand to benefit from emerging automation and analysis capabilities

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