Fire Resistance of Conveyor Belts
Conveyor belt fires can present a serious hazard in the confined environment of an underground coal mine. To minimize this hazard, Federal regulations were enacted following the Federal Coal Mine Health and Safety Act of 1969 to require the use of acceptable fire-resistant conveyor belts and suitable belt slippage-sequence switches, fire warning devices, and fire […]
Crushing of Mica Ore
Crushing of mica prior to pneumatic processing technique were studied for concentrating coarse mica. Muscovite and phlogophite are the two major commercial mica minerals. However, this research was conducted exclusively with muscovite, and throughout this paper mica will mean muscovite. Two primary forms of commercial mica are (1) sheet mica and (2) scrap and flake […]
Cone Crushing, Rod Milling and Ball Milling Laboratory Testing
The two largest cost components in comminution circuits are energy consumption and metal wear which, for cone crushing, rod milling and ball milling, can be established by conducting laboratory bench scale tests. Pilot plant testing for these comminution methods is not normally required. Laborary testwork performed by Allis-Chalmers to identify these parameters are covered by: […]
How Ball Mill Ore Feed Size Affects Tonnage & Capacity
The important of crushing your ore and rock fine and properly is often forgotten. The finer you crush, the higher your ball mill tonnage and capacity will be. The effect of ball mill feed size and how it affects circuit throughput can be hard to estimate. Here we described a method of designing a crushing […]
Rock Splitting
Rock splitting utilizes a tensional force to crack the rock. This is achieved by inserting a split steel shank in a drillhole and driving a steel wedge between the center of the split shank thereby producing the tensile forces. The advantages of the rock splitting technique over blockholing are the absence of explosives and the […]
Rock Grapple
A rock grappler is a claw shaped device used for picking up boulders. The grasping mechanism of a grappler is generally activated by a pneumatic or hydraulic cylinder, as shown in Figure 17. The cylinder is connected to each half of the claw and when activated forces the claw shut. Grapplers are used to remove […]
Rock Hammering & Rock Breaking
The rock hammering method of boulder breaking is a process of hammering the boulder by either a hydraulic or pneumatic hammer until the boulder breaks. The hammer is usually mounted on a boom. The motor, hydraulic pump, and oil reservoir are usually located near the boom. Figure 14 shows a typical hammer installation. The advantages […]
Rock Boulder Blasting with Explosive
Boulders can be broken up using either explosives or mechanical methods which can be implemented in many ways. Handling boulders hung up in crushers is inherently inefficient for the overall operation, and the techniques in handling them each have their own advantages and disadvantages. Table 4 shows a comparison of explosive boulder breaking techniques. When […]
Rock Boulder Exploding Techniques
Several products have come on the market in recent years that improve the safety of secondary blasting operations. The most significant of these are binary explosives, exploding bridgewire electric blasting caps, and nonelectric systems. Binary Explosives Binary explosives are two nonexplosive materials that become cap sensitive, high energy explosives when mixed. One part can be […]
Rock Boulder Crushers
In mining and quarryinq, the mineral commodity as present in the ground may be composed of rock blocks that must be reduced in size, to suit market requirements. The rock in place will be blasted, loosened, and then hauled away to the first processing step-size reduction. As delivered from the blasting area the rocks will […]