Clinker (waste)

Clinker is a general name given to waste from industrial processes — particularly those that involve smelting metals, burning fossil fuels and using a blacksmith's forge which will usually result in a large buildup of clinker around the tuyere. Clinker often forms a loose, black deposit that can consist of coke, coal, slag, charcoal, grit, and other waste materials.

Clinker may be reused for paving footpaths. It is laid and rolled, and forms a hard path with a rough surface.

Clinker often has a glassy look to it. It is much heavier than coke.

Etymology

"Clinker" is from Dutch, and was originally used in English for bricks – see clinker brick. The term was later applied to hard residue, due to similar appearance.

Uses

In sewage treatment works, the water is first of all screened to remove floating debris. Then it is sedimented to remove small insoluble impurities. After this, it is sprayed over a filter bed of clinker, where microbes in the clinker kill harmful anaerobic bacteria in the water.

Waste

Waste and wastes are unwanted or unusable materials. Waste is any substance which is discarded after primary use, or it is worthless, defective and of no use.

The term is often subjective (because waste to one person is not necessarily waste to another) and sometimes objectively inaccurate (for example, to send scrap metals to a landfill is to inaccurately classify them as waste, because they are recyclable). Examples include municipal solid waste (household trash/refuse), hazardous waste, wastewater (such as sewage, which contains bodily wastes (feces and urine) and surface runoff), radioactive waste, and others.

Definitions

United Nations Environment Program

According to the Basel Convention,

United Nations Statistics Division, Glossary of Environment Statistics

European Union

Under the Waste Framework Directive, the European Union defines waste as "an object the holder discards, intends to discard or is required to discard."

Types

There are many waste types defined by modern systems of waste management, notably including:

Waste (play)

Waste is a play by the English author Harley Granville Barker. It exists in two wholly different versions, from 1906 and 1927. The first version was refused a license by the Lord Chamberlain and had to be performed privately by the Stage Society in 1907; the second was finally staged in public at the Westminster Theatre in 1936.

Plot

The plot centres around ambitious independent politician Henry Trebell, his plans for a bill to disestablish the Church of England and his fall from grace and suicide after his affair with married woman Amy O'Connell, who dies after a botched abortion. The title may refer to the waste of his potential talents due to the scandal, the loss of the disestablishment bill and the termination of Amy's pregnancy.

Dramatis personae (1927 version)

Waste (disambiguation)

Waste is unwanted or undesired material.

Waste, WASTE or W.A.S.T.E. may also refer to:

Clinker

Clinker may refer to:

Clinker may also be used for:

People with the surname Clinker

Clinker (cement)

In the manufacture of Portland cement, clinker occurs as lumps or nodules, usually 3 millimetres (0.12 in) to 25 millimetres (0.98 in) in diameter, produced by sintering (fused together without melting to the point of liquefaction) limestone and alumino-silicate materials such as clay during the cement kiln stage.

Composition and preparation

Clinker consists of various calcium silicates including alite and belite. Tricalcium aluminate and calcium aluminoferrite are other common components. These components are often generated in situ by heating various clays and limestone.

Portland cement clinker is made by heating a homogeneous mixture of raw materials in a rotary kiln at high temperature . The products of the chemical reaction aggregate together at their sintering temperature, about 1,450 °C (2,640 °F). Aluminium oxide and iron oxide are present only as a flux to reduce the sintering temperature and contribute little to the cement strength. For special cements, such as low heat (LH) and sulfate resistant (SR) types, it is necessary to limit the amount of tricalcium aluminate formed. The major raw material for the clinker-making is usually limestone mixed with a second material containing clay as source of alumino-silicate. Normally, an impure limestone which contains clay or silicon dioxide (SiO₂) is used. The calcium carbonate (CaCO₃) content of these limestones can be as low as 80%. Second raw materials (materials in the rawmix other than limestone) depend on the purity of the limestone. Some of the second raw materials used are: clay, shale, sand, iron ore, bauxite, fly ash and slag. The clinker surface and its reactions in different electrolytic solutions are investigated by scanning electron microscope and atomic force microscopy.

Clinker (boat building)

Clinker built (also known as lapstrake) is a method of boat building where the edges of hull planks overlap, called a "land" or "landing." In craft of any size planks are also joined end to end into a strake. The technique developed in northern Europe and was successfully used by the Norsemen and typical for the Hanseatic cog. A contrasting method, where plank edges are butted smoothly seam to seam, is known as carvel construction.

Examples of clinker-built boats directly descended from those of Norsemen shipbuilders are the traditional round-bottomed Thames skiffs of the River Thames, and the larger (originally) cargo-carrying Norfolk wherries of England.

Origin

The technique of clinker developed in the Nordic (Germanic) shipbuilding tradition as distinct from the Mediterranean mortise and tenon planking technique which was introduced to the provinces of the north in the wake of Roman expansion. Overlapping seams already appear in the 4th century BC Hjortspring boat. The oldest evidence for a clinker-built vessel, dendrochronologically dated to 190 AD, are boat fragments which were found in recent excavations at the site of the famous Nydam Boat. The Nydam Boat itself, built ca. 320 AD, is the oldest preserved clinker-built boat. Clinker-built ships were a trademark of Nordic navigation throughout the Middle Ages, particularly of the longships of the Norsemen explorers and the trading cogs of the Hanseatic League.