Coarse crushing

Ores must be ground to a point of complete or nearly complete liberation, Even though this might possiblv be accomplished bv coarse crushing, grinding to finer than 10 mesh in all cases and finer than 48 mesh in most cases is necessaiw prior to Rotation, (Grinding is done in closed circuit with classifiers. 

A flow sheet for one iron ore process is shown in Fig. 20-56. For the grinding of softer copper ore the rod mill might be eliminated, both coarse-crushing and baU-milhng ranges being extended to fill the gap. 

High-permeability passive perimeter gas control systems entail the installation of highly permeable (relative to the surrounding soil) trenches or wells between the hazardous waste site and the area to be protected (Figure 16.6). The permeable material offers conditions more conductive to gas flow than the surrounding soil, and provides paths of flow to the points of release. High-permeability systems usually take the form of trenches or wells excavated outside the site, then backfilled with a highly permeable medium such as coarse crushed stone. 

The bed was first operated at the preselected conditions at a steady state then about 455 kg of the coarse crushed-acrylic particles, similar to that used as the bed material but of sizes larger than 6-mesh, were injected into the bed as fast as possible to serve as the tracer particles. Solids samples were then continuously collected from five different sampling locations at 30-second intervals for the first 18 minutes and at 60-second intervals thereafter. The samples were then sieved and analyzed for coarse tracer particle concentration. Typical tracer particle concentration profiles vs. time at each sampling location are presented in Figs. 38-42 for set point 3. 

Kick s law is used as the present case may be regarded as coarse crushing. 

The size range involved by be considered as that for coarse crushing and, because Kick s law more closely relates the energy required to effect elastic deformation before fracture occurs, this would be taken as given the more reliable result. 

Various grey and black marls from the coal-beds mixed together with tire addition of from twenty to twenty-five per cent, of coarsely-crushed old biscuit... 

Metallurgical grade silicon is marketed in a coarsely crushed form or as a finely ground powder in different particle sizes. Powders with increased purity due to acid washing, particularly for the removal of metallic impurities, are specialty products. They are utilized, for example, in the manufacture of silicon nitride powder or reaction-bonded silicon nitride ceramic components and are therefore the starting materials for engineering ceramic specialties. 

Use of the Field tube for determining the performance of coals is limited by the short residence time of 0.3 seconds (2.1 m) and the inability to use particles larger than 0.14 mm. This limits the extent of particle size changes and the structure of the mineral substance relative to pulverized fuels or coarse-crushed brown coals used in utility boilers. This difference probably has an effect on the formation of deposits. 

Coarse crushing (jaw or roller) Contamination, cross-contamination... 

Monosized pieces in bulk, on the other hand, particularly if they are not spherical, do not reach high density or mass. For example, run-of-mine, coarsely crushed coal that is loaded into trucks, railroad cars, or ship holds results in relatively high bulk mass, as smaller particles fill the voids between larger ones. If that same coal is briquetted, the identical transport device holds much less and, therefore, in comparison, renders shipping less economical. Crushing briquettes and sizing the broken pieces to be within the same limits as run-of-mine coal results in identical bulk mass and meets standard loading requirements. 

For vitrinite reflectance (Rq) measurements, coarsely crushed samples were acidified with hydrochloric and hydrofluoric acid to remove carbonate and silicate. The solution was then centrifuged with heavy liquid to separate kerogen. The kerogen was embedded in a resin plug and polished to a flat shiny surface. Measurements of the percentage of incident light reflected from vitrinite particles under oil immersion with a Carl Zeiss MPM-03 microspectrophotometry system were made. 

Waste rock generally consists of coarse, crushed, or hlocky material covering a range of sizes, from very large houlders or blocks to fine sand-size particles and dust... 

As for the coarse soil material (gravels and sands) or coarse crushed material, relevant information regarding the resilient modulus can be found in Section 10.5.6. 

The coarse crushed aggregates should have resistance to fragmentation by Los Angeles lower than 30%, when tested in accordance with ASTM C 131 (2006). 

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