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2012年(136)

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分类: 网络与安全

2012-02-24 08:46:29

Natural sand refers to weathered and worn out particles of rocks and is of various grades or size depending on the accounting of wearing. Its main natural and cheapest source is river. Dams are constructed on every river so that these sources are erasing very fast. Nowadays excellent sand is not readily available, but if you need it, you should transport from other places with long distance. Those sources are also exhausting very rapidly. So it is a need of the time to find some substitute to natural river one. Even though manufacturing of artificial one requires more energy than corresponding production of natural, the vicinity to the market, with less transport, will make it environmentally favorable. Then here comes the artificial sand. Next Hongxing Machinery expert will explain how it is manufactured and used.

When manufacturing it, it is possible to select the raw material, for example, the parent rock. Properties of the parent rock are determined by various petro logical parameters that have an important influence, both upon the blasting and crushing of it, for example, energy consumption, fines production and shape, but also upon the quality of fresh and hardened concrete.

In order to tailoring the end product for specific purposes, it is important to know how these properties are influencing the end product. It is experienced that lithology has not so much impact on geometric properties for its fraction; however it may govern these properties for the fines. The effects of secondary minerals on properties and quality of the fines, for use in concrete, are only partly known. This needs to be examined further.

In order to reach a high-quality final result, each stage needs to be optimized – it is not a good approach to try to repair an insignificantly crushed product by the final crushing stage alone. The installation of has proved to be an effective way of producing cubical (even rounded) particles in the small and medium size fractions ( approx 5 mm). It is however a challenge to avoid generating of a high percentage of fines. The latest generation of equipment combined with the latest development of air classification has, however, enabled to govern the grading curve very precisely, including the finest part. Configurations of machinery from e.g. Metso/Buell or the V7 concept from Kemco in Japan are good examples, where manufactured sand has been produced for 100% use in concrete.

However, it is important to realise that high quality aggregates could be degraded by insufficient procedures of handling and storage.

A new understanding of its properties and the need to treat it differently is required.

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