S |
| SA |
| See Sustainability Appraisal. |
| SAC |
| Special Areas of Conservation are areas where habitats and species are required to be maintained or restored under the Habitats Directive (Directive 92/43/EEC on the Conservation of Natural Habitats and of Wild Fauna and Flora). Further information can be found in the Nature Conservation section of this website. |
| Sand |
| In civil engineering, sand is the finest grade of aggregate (see also Particle Size). Generally, the term sand is used for material between 0.063 mm and 4 mm. For use in asphalt 2 mm is the dividing point between coarse and fine aggregate. For use in concreting sand material less than 5 mm is used, and there are further restrictions on particle size distribution [BS 882; 1983]. |
| Sand screw |
| Machine with three related functions: washing, dewatering, and classification. It consists of an inclined steel vessel with an internal screw which tumbles the water-suspended material, causing attrition and cleaning. Excess water drains off as the material passes up the vessel. It can also be called a fine material washer. |
| Sandstone |
| Sedimentary rock made of fragments of sand size in a finer grained matrix or cementing material, sand particles are predominantly quartz. |
| Saxon |
| The period between the Roman departure and the Norman conquest. Also sometimes referred to as the early medieval period. |
| Scaled Distance |
| Scaled Distance is the parameter which is related to the level of vibration from a blast. SD = distance / ?MIC, where distance is the distance in metres from blast to monitoring location and MIC is Maximum Instantaneous Charge. |
| Scalping |
| Separation of fine material [to bypass a stage] in comminution. |
| Scalpings |
| Fine (undersize) waste. |
| Scalpings are, correctly, the off-cuts or shards created by dressing stone for building work. It can more generally refer to quarry waste. |
| Scoping |
| A preliminary environmental assessment of the impact area, the likely impacts and the potential mitigation measures associated with a particular development. |
| Scraper |
| Mechanical device for removing a layer (usually soil or loose material) and transporting it away. |
| Screen efficiency |
| The ratio of the mass of undersize material passing through a screen to the mass of undersize material in the feed, expressed as a percentage. |
| Screening |
| Method of particle size separation (sizing) by means of a screen (flat sieve-like structure) of specified aperture. The process is usually carried out with water, but dry screening is also used to produce building sand. |
| Scrubber barrels |
| Rotating steel drums with a water spray for washing of clay and other fine material from mineral particles. |
| Scrubbing |
| Mineral processing operation in which adherent fines or clay coatings are washed off the surfaces of larger aggregate particles see scrubber barrels. |
| SEA |
| See Strategic Environmental Assessment. |
| Secondary Aggregate |
| Includes by-product mineral waste, synthetic materials and soft rock (shale) used with or without processing as a secondary aggregate. |
| Secondary crusher |
| 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. |
| Secondary Crushers |
| The process whereby material from the primary crusher is reduced to 40 - 60mm in size. |
| Secondary fragmentation |
| The breaking of oversize rocks following primary blasting to enable them to be transported to the primary crusher. This can be achieved by the use of explosives, a drop ball, or the use of hydraulic breakers (hammers or peckers). |
| Section 106 |
| Section 106 Agreements can be used to add conditions to development where it is not appropriate to use a condition in the planning permission. They also enable the Local Authority to secure provision or improvement of existing infrastructure necessary to meet the needs of the occupiers or users of new development. This is done by way of land or finance contributions. Section 106 Agreements may enhance the quality of development and enable proposals to go ahead which might otherwise be refused. Such Agreements should be relevant to planning, directly related to the proposed development and necessary to make it acceptable in land-use planning terms. |
| Sedimentary |
| These are rocks which are formed from material derived from pre-existing rocks by processes of erosion (sandstone is formed in this way), or from material of organic origin (coal and chalk is formed in this way). |
| Sedimentary rocks |
| Rocks formed from material derived from pre-existing rocks by processes of weathering, transport, deposition and other organic components. They include rocks such as limestone, clay and sandstone. |
| SEERAD |
| Scottish Executive Environment and Rural Affairs Department. www.scotland.gov.uk |
| Seismic Waves |
| Seismic waves are vibration which travel through the ground. The different types can be divided into to types, those which travel through the rock (body waves) and those which travel along a boundary such as the earth's surface (surface waves). The distance travelled will depend on the size of the source of vibration (e.g. blast) and the nature of the rock through which the waves travel. |
| Semi-autogenous crushing |
| Crushing or milling which is achieved partly by the interaction between particles of the feed material. See autogenous crushing. |
| SEPA |
| Scottish Environment Protection Agency. www.sepa.org.uk |
| Severance |
| In this context it means the cutting of a road, path or track, so that it no longer forms a continuous route. |
| Shear |
| The distortion caused by two opposing, parallel forces. |
| Sieve bend |
| Curved metal screen (often with vibrating action) with apertures set at the desired spacing. Feed is passed over the screen as a slurry and the over- and undersize fractions collected for further processing. |
| Sieve mapping |
| Technique for mapping environmental constraints, working from a series of overlays, sieving out areas that are relatively free of constraints. |
| Silica Sand |
| Sandstone which contains a high proportion of silica (99% SiO2) in the form of quartz. Low levels of impurities such as iron (<0.035% for clear glass, <0.3% for coloured glass) are important, as is grain size (0.5mm to 0.1mm) |
| Silt lagoons |
| Contained volume of water allowing time for settling out of fines to allow reuse of water in aggregate processing. |
| Silt |
| Mineral particles with a grain size below 0.063 mm which are not clay minerals. |
| Single size aggregates |
| Product with size range between two specified adjacent screen sizes. Typically 28-40 mm, 20-28 mm, 14-20 mm, 10-14 mm and 6-10 mm. |
| Single toggle jaw crusher |
| A jaw crusher where one jaw is suspended from an eccentric pivot and can move both vertically and horizontally, having one toggle plate. |
| Site Factors |
| Vibration amplitude (measured in PPV) is related to Scaled Distance (SD) by the following equation: PPV = a(distance/?MIC)b. a and b are known as the site factors which are obtained through monitoring and regression analysis |
| Site of Special Scientific Interest (SSSI) |
| Site of Special Scientific Interest. A designation for nature conservation, given specific protection in law. It can be for biological or geological-geomorphological significance, or a combination of both. |
| Site Water |
| Water which naturally collects within the boundary of a site, through precipitation or groundwater seepage. |
| Smoke |
| BS 6069 (Part 2) defines 'smoke' as particulate matter that is in the size range 0.001 - 1microns in diameter. |
| SMR |
| Sites and Monuments Record. The repository for all archaeological and historical information relating to a county or district. It can also refer to the person responsible for the record |
| Soil |
| In engineering terms, soil is defined as all un-lithified (un-cemented) material overlying the bedrock. |
| Soiling Unit (SU) |
| Soiling unit. A measure of the dustiness of an exposed slide, obtained by subtracting the reflectance value from 100. |
| Sound Power Level (SWL) |
| The amplitude (or level) of sound output from a particular source, measured in decibels (dB). It can be used to predict the sound level at a given distance from the source. |
| Sound Pressure Level (SPL) |
| This can also be referred to as the sound amplitude and is the pressure exerted by the air. It is usually measured in microPascals but can be converted into decibels (dB). |
| Source |
| See also emission, point source, line source and area source. The origin of dust emissions. |
| SPA |
| The Birds Directive (Directive 79/409/EEC on the Conservation of Wild Birds) affords protection, management and control of all naturally occurring species of wild birds in Member States. Special measures are also required to conserve the habitats of certain particularly rare species or migratory species in Special Protection Areas (SPAs) which are classified by the Secretary of State. Further information can be found in the Nature Conservation section of this website. |
| Special Area of Conservation (SAC) |
| Special Areas of Conservation are areas where habitats and species are required to be maintained or restored under the Habitats Directive (Directive 92/43/EEC on the Conservation of Natural Habitats and of Wild Fauna and Flora). Further information can be found in the Nature Conservation section of this website. |
| Special Protection Area (SPA) |
| The Birds Directive (Directive 79/409/EEC on the Conservation of Wild Birds) affords protection, management and control of all naturally occurring species of wild birds in Member States. Special measures are also required to conserve the habitats of certain particularly rare species or migratory species in Special Protection Areas (SPAs) which are classified by the Secretary of State. Further information can be found in the Nature Conservation section of this website. |
| Spiral screw |
| Steel pipe with an internal conveyor screw or spiral. Material moves forward as the screw is rotated. The direction can be horizontal, inclined or vertical, and it can be used wet or dry. It is also used in dredging to recover material from the river or sea bed. |
| SPL |
| See Sound Pressure Level. |
| SSSI |
| See Site of Special Scientific Interest. |
| Stakeholders |
| Individuals or organisations with an interest (financial or intellectual) in a business (such as a quarry company), an activity (such as quarrying) or a location (such as a quarry). |
| Standard Error |
| There seems to be a lot of variation in the name given to the parameter which is required here. The term most often used is Standard Error or Standard Error of Estimate and actually refers to the square root of the residual (predicted y minus actual y) mean square. It has also been referred to as: Standard Error of Regression, Estimate of Standard Deviation of Error, Residual Standard Deviation and Root Mean Square Error The term Standard Error is more correctly applied to the standard deviation of the sampling distribution and should apply to the X variable (gradient) and the intercept, as shown in the Excel regression table. |
| Static classifiers (gravitational) |
| Machines that separate particles into size fractions allowing particles to fall under gravity in an air stream. Separation is achieved by changing the direction of the main air stream, allowing denser particles to continue downwards; or by injection of air across the particle stream to extract lighter particles. |
| Stationary screen |
| Sloping static device for separating different rock size fractions by means of metal bars or grids with apertures set at the desired spacing. Feed is passed onto the screen and the over- and undersize fractions collected for further processing. See also grizzly. |
| Statutory Nuisance |
| A legal term for a class of nuisance prohibited by civil law. |
| Stemming |
| Material placed in the top of a blast hole, overlying the explosive, which prevents all the explosive energy blowing out of the top of the hole. |
| Sterilisation |
| The removal of access to potentially economically workable mineral resources by legislation (designated environmental constraint areas etc) or by other developments (transport, housing, industry etc). |
| Sticky Pad |
| An obscuration gauge first described by Beaman & Kingsbury (1981). In simple terms it is a square of adhesive paper, three quarters of which is exposed to the air for deposited dust to adhere to. The unexposed quarter is used as a reference surface against which the exposed surface is assessed. |
| Stockpiling |
| The temporary storage of potentially saleable products to meet future anticipated demand or to provide flexibility in the quarry operations by storing sufficient material of a particular type to make a processing option worthwhile. |
| Strategic Environmental Assessment (SEA) |
| Strategic Environmental Assessment assesses the environmental impact of plans and programmes prepared by public bodies. Further information here. |
| Stripping |
| The removal of overburden. |
| Study area |
| Extent of area, as identified in the desk study, which may be subject to landscape and/or visual effects as a result of proposed development and which must therefore be covered by field survey |
| Sub-economic |
| That part of the mineral reserve or resource which is uneconomic to recover at current costs, but may be in the future. |
| Sub-soil |
| The layer of material laying underneath top soil which nevertheless contains some organic matter and is capable of sustaining life. |
| Surfactant |
| Surfactants are compounds that lower the surface tension of a liquid, allowing easier spreading, and lowering of the interfacial tension between a liquid and a solid. |
| Sump |
| A collection point for water at the lowest point of an excavation, from where it can be pumped away, thus keeping the excavation dry. |
| Surface cover |
| Soil or overburden lying above the desired mineral resource. |
| Surface Water |
| Water which remains on the surface of the earth, in the form of drains, streams, rivers, lakes, etc. |
| Suspended solids |
| Solid particles suspended in a fluid medium (usually water). |
| Sustainability Appraisal (SA) |
| Sustainability Appraisals identify and report on the ability of particular plans to achieve social, environmental, economic and resource objectives. |
| Sustainable Development |
| A key objective of sustainable development is the need to secure an adequate supply of minerals to meet economic needs, whilst minimising the potential adverse effects of mineral extraction on the environment. |
| Sward |
| Land covered with grassy turf |
| Swing jaw |
| The moving plate in a jar crusher. |
| SWL |
| See Sound Power Level. |
| TOP |
T |
| Tensile fracture |
| Fracture in rock that forms and propagates parallel to the direction of the maximum compressive stress. |
| Tensile |
| The stress of stretching or elongation. It can be thought of as negative compression. |
| Tertiary crusher |
| The final crushing stage before other processing options are undertaken. Typically reduces the size to below 20 mm. |
| Thickener |
| This is a mechanical device for increasing the solid/water ratio in a slurry. It consists of a large circular tank with rotating stirring arm. Solids settle and are removed as an underflow while clarified water overflows |
| Throw |
| The amount of movement between the moving and stationary crushing surfaces is known as the throw of the crusher, This applies to jaw and cone crushers. |
| Tillage |
| In conservation tillage, crops are grown with minimal cultivation of the soil. When the amount of tillage is reduced, the stubble or plant residues are not completely incorporated, and most or all remain on top of the soil rather than being ploughed or disced into the soil. |
| Tip speed |
| The relative velocity at the end of the rotor in an impact crusher, within the range 35 to 90ms-1. |
| Toggle |
| Component of the actuating mechanism of a jaw crusher. |
| Toggle plate |
| The bottom of the pitman (jaw) is braced with a cast steel or iron toggle plate; this is often hydraulically controlled to alter the crusher product outlet and also acts as a release mechanism for 'uncrushable' material such as tramp iron. |
| Tooth profiles |
| These are the different design of liner plates in jaw crushers. They may have a standard 'Z-type' (symmetrical, flat corrugation), NC (non-choke), CC (coarse corrugation) and WW (wide wave) profile. |
| Top-soil |
| The uppermost layer of soil, rich in organic matter and forms of life. |
| Trail dredging |
| Extraction of marine aggregates: a suction pipe is pulled across the seabed at a slow speed. This extracts material in a shallow trench 2.5m wide by 0.25m deep; it allows working of relatively thin deposits. |
| Tramp Iron |
| Bolts, shovel teeth, picks and other uncrushable metal that is often present in crusher input material. |
| Transfer |
| Movement of material from one part of the process plant to the next. |
| Transfer Functions |
| This is a mathematical procedure which attempts to define the relationship between the values recorded at two different points, the purpose being to be able to predict the values at one, given the values at the other. This can be a simple factor for the PPV values (e.g. the values at point B is always approximately twice that at point A) or it can be more complex and seek to predict the entire seismic signal. Any Transfer Function requires a good set of data. |
| Transpiration |
| Process by which water that is absorbed by plants, usually through the roots, is evaporated into the atmosphere from the plant surface, such as leaf pores. |
| Type-I sub-base |
| Layer of granular aggregate used in road construction below the roadbase. The specification and thickness varies with the intended application. |
| TOP |
