| Cambridge roller |
| This is made of iron rings and when pulled over soil prepared to a fine consistency it will leave small ridges. www.greenheyes.com/pages/rollers01.htm |
| Cartographic |
| Concerning maps and charts.
|
| Catchment Area |
| A land area where precipitation runs off into streams, rivers, lakes, and reservoirs. It is a land feature that can be identified by tracing a line along the highest elevations between two areas on a map, often a ridge. Large drainage basins, like the area that drains into the River Severn contain thousands of smaller drainage basins. |
| Cavity |
| The crushing chamber of a crusher. |
| Centrifugal separators |
| Hollow tubular vessels where water containing suspended solids is fed tangentially to induce a vortex. The solids move to the walls of the vessel under centrifugal force while clear water is drawn out of the centre of the tube. |
| Choke feeding |
| Operating the crusher with a completely filled crushing chamber. This allows a greater degree of rock-on-rock crushing which helps to reduce wear in the crusher. |
| Choke Point |
| Location in the crushing chamber with the minimum cross section. All compression type crushers have choke points. |
| Classification |
| Method of particle size separation by means of differences in settling velocity in water or occasionally, air (applicable to finer particles). |
| Classifier |
| A device which sorts particles by their size, shape or density by means other than screening. |
| Clay |
| Clay has two definitions. a) Any rock or mineral fragment with a diameter less than 0.002 mm. (b) A loose, earthy, extremely fine-grained, natural sediment or soft rock composed primarily of clay-size or colloidal particles and containing a considerable amount of clay minerals (hydrous aluminium silicates). |
| Cleavage planes |
| Parallel, closely spaced, planes within a rock or mineral along which it tends to split. Slate and mica are examples of a well cleaved rock and mineral respectively. |
| Climate change |
| Variations in the earths global climate over time. These may include global warming or cooling and can be caused by natural or anthropogenic processes. |
| Closed side setting |
| The product outlet size is defined by its closed side setting. This is the point where the crushing surfaces are the closest together at the product discharge outlet. See also closed side setting. |
| Comminution |
| The process of breaking into small fragments, bringing about a reduction of particle size. |
| Compensation |
| the measures taken to offset or compensate for residual adverse effects that cannot be mitigated, or for which mitigation cannot entirely eliminate adverse effects. |
| Compression |
| One of the two main crushing methods (definition: the act of squeezing/ pressing between rigid surfaces). |
| Compressive |
| The stress of being pressed or squeezed together. |
| Concrete |
| Concrete is a construction material containing aggregates with dimensions greater than 5mm mixed with specific proportions of cement and water, plus various additives to promote setting, prevent freezing and vary the colour etc. |
| Cone crusher |
| A cone crusher consists of a main vertical shaft with a conical head (known as the convex or head) and an inverted cone (known as the bowl or concave) that sits over it. Cone crushers operate a continuous crushing cycle, with crushing taking place in the chamber 100% of its operating time. |
| Constraints map |
| map showing the location of important resources and receptors that may form constraints to development. |
| Containment |
| The deliberate retaining of material, such as waste or dust, by the construction of a suitable feature or facility (dam, bund, lining or building) to prevent its uncontained escape. It can also be created by natural features. |
| Contamination |
| The natural, accidental or deliberate mixing or combination of a substance with non-specification solid, liquid or gas. |
| Controlled waste |
| Any waste subject to the provisions of the Control of Pollution Act 1974 (COPA, as amended) and the Environmental Protection Act (EPA). Controlled wastes are: commercial and industrial waste (including construction and demolition waste); household waste. |
| Conveying |
| The transport of materials by a conveyor. |
| Conveyor |
| A moving, endless, flexible belt, usually made of rubber compounds, supported by a steel frame, which passes round powered pulleys at each end of the belt and is supported by idler rollers. |
| Correlation Coefficient |
| This is a measure of the degree to which two variables are related by a simple linear relationship. With blasting, the variables are the log values of PPV and Scaled Distance. A value of 1 gives a perfect relationship and a value of 0 gives no relationship. |
| Coupling |
| Attaching the transducer to the ground or foundation in such a way as to ensure there is no jumping or slipping which would mean the recordings would not reflect the true ground motion. |
| Crushed rock aggregate |
| Primary aggregate comprising crushed hard rock. |
| Crusher |
| A device for breaking rock in which the components contacting the rock follow a controlled pattern. Crushing is one of the most critical operations in the aggregate process. |
| Crusher run (aggregate) |
| Material produced by simple crushing, with a range of sizes, often referred to as 'all-in'. |
| Crushing |
| The breaking of run of mine rock to reduce its size for further processing to suit customer requirements. See also Crusher and Crushing. |
| Crushing (primary) |
| The primary crusher is the initial crushing operation on run of mine rock to reduce its size for further processing. It generally reduces the maximum size of rocks from under 1.5 m to under 0.3 m. |
| Crushing (secondary) |
| Takes material from the primary crusher and reduces its size further, typically to below 40 or 50 mm. The size and shape of the product is of importance, so cone crushers are usually employed.
|
| Crushing (tertiary) |
| The final crushing stage before other processing options are undertaken. Typically reduces the size to below 20 mm. |
| Crystalline silica |
| Natural or artificial silica (SiO2). It can be a health risk (silicosis) if fine dust from operations (cutting, sawing, drilling etc.) is breathed in by humans. Activities which may expose workers to silica are subject to the Control of Substances Hazardous to Health Regulations 2002 (COSHH). |
| CSS |
| Closed Side Setting. The product outlet size is defined by its closed side setting. This is the point where the crushing surfaces are the closest together at the product discharge outlet. See also closed side setting. |
| Curtilage |
| The enclosed land around a building.
|
| Cyclone |
| Conical classifying device. Material is fed in as a pulp or slurry in water (see hydrocyclone) or as dry particles in air. The centrifugal force as the material is swept round the device separates particles of different density or size. |