Refining of crushed sand as a substitute for natural sand (e.g. for use in the production of concrete, asphalt, etc.)

Abstract

Refining of crushed sand as a substitute for natural sand, characterized in that the counter-rotating discs for rounding off crushed sand grains consist of natural mineral material.

Description

For the production of concrete, asphalt, etc., sand (grains 0-2 mm) are required as filler. In order that the product (concrete, asphalt, etc.) can also be easily processed during installation, the sand grains must have curvatures. These curvatures are given in natural sand. Natural sand is a natural product and is also mined, for example, in gravel pits. In the meantime, many gravel pits or otherwise have occurred. Since natural sand has become a rare raw material (and correspondingly expensive). Furthermore, many gravel pits are in the area of larger river waters (e.g. rhein), the sand conveyed there must be transported over long distances to the processing plants (with corresponding CO 2- production).In quarries, crushing sand is produced as waste product during the production of chips. In contrast to natural sand, the crumbs of crushing sand are not rounded, but rather are very angular and edged. For this reason, crushing sand can only be used in narrow quantities as a substitute for natural sand (for poorer processing).For this reason, it has been investigated whether a method of rounding the grit grains to be used as a substitute for natural sand is possible. This study has been successful.1. Construction:The crushing sand is subjected to an external movement (similar to the natural production of sand: in river waters the grains are crushed and rounded by movement and abutment with other grains / rocks over time). These movements acting from the outside can be supported by air, but also by water.For this purpose, the crushing sand grains are placed between two disks rotating in the opposite sense (distance of the disks corresponds to the grain diameter) and subjected to a movement. The sand is now filled from the inside of the upper pane and moved outwards. During the movement, the angular edges round off.Another possibility is to move in a drum mill. Here, the grit grains are rounded by contact with each other. Further rounding devices can be used as long as the material to be rounded is not comminuted. Therefore, the rounding process used must be matched to the starting material (=the material to be rounded). Also, the materials to be rounded must not remain active for too long in the rounding device, since otherwise comminution could take place.In these types of mills, the crushing sand grains should not be ground but rather merely rounded. Therefore, the final result is to be taken into account in each milling test.2. Benefit: BenefitThe upgraded fracturing sand can be made in any stone fracture and can serve as a substitute for natural sand.Thus, the following can be used:the natural deposits for sand are saved,long transport paths from the sand deposit to the processing unit are dispensed with,saving CO 2 by omitting transport paths,the waste product crushing sand can be used in large quantities.Furthermore, the method can also be used for rounding recycling sands (preparation of concrete, construction debris, etc.). Subsequent rounding of natural sand is also possible.

Claims

Refining of crushing sand as a substitute for natural sand, characterised in that the counter-rotating discs for rounding of crushing sand grains consist of natural mineral materialRefining of crushing sand as a substitute for natural sand, characterised in that the counter-rotating discs for rounding of crushing sand grains consist of artificial mineral materialRefining of crushing sand as a substitute for natural sand, characterised in that the counter-rotating discs for rounding the grains of crushing sand consist of concrete,Refining of crushing sand as a substitute for natural sand, characterised in that the counter-rotating discs for rounding of crushing sand grains consist of metalRefining of crushing sand as a substitute for natural sand, characterised in that in the case of the oppositely directed discs only one disc is driven and the other disc is stationaryRefining of crushing sand as a substitute for natural sand, characterised in that in the case of the oppositely directed discs only one disc is driven, the other disc is moved along in the oppositely directed sense via toothed wheels or the likeRefining of crushing sand as a substitute for natural sand, characterised in that the counter-rotating discs can be driven under speed controlRefining of crushing sand as a substitute for natural sand, characterised in thatthe material to be rounded can be added via the central axisRefining of crushing sand as a substitute for natural sand, characterised in that the rounding of the crushing sand grains takes place by means of a drum millRefining of crushing sand as a substitute for natural sand, characterised in that the drum mill has an axial material inletRefining of crushing sand as a substitute for natural sand, characterised in that the drum mill is equipped with a speed-controlled driveRefining of crushing sand as a substitute for natural sand, characterised in that the size of the drum mill is adapted to the material throughputRefining of crushing sand as a substitute for natural sand, characterised in that a further opening is provided in relation to the material inlet for the material outletRefining of crushing sand as a substitute for natural sand, characterised in that the mill is stopped and opened to take out the material to the material outletRefining of crushing sand as a substitute for natural sand, characterised in that the mill is stopped and opened for the material outflow, the opening is located at the bottom (outflow of the material by means of gravity)Refining of crushing sand as a substitute for natural sand, characterized in that the drum mill consists of metalRefining of crushing sand as a substitute for natural sand, characterised in that the drum mill consists of plasticRefining of crushing sand as a substitute for natural sand, characterized in that the drum mill consists of rubber and / or of rubber-like materialsRefining of crushing sand as a substitute for natural sand, characterized in that the drum mill is operated with auxiliary rounding materialsRefining of crushing sand as a substitute for natural sand, characterized in that ball mills can be usedRefining of crushing sand as a substitute for natural sand, characterised in that the ball mill has an axial material feedRefining of crushing sand as a substitute for natural sand, characterised in that the ball mill is equipped with a speed-controlled driveRefining of crushing sand as a substitute for natural sand, characterised in that the size of the ball mill is adapted to the material throughputRefining of crushing sand as a substitute for natural sand, characterised in that a further opening is provided in relation to the material inlet for the material outletRefining of crushing sand as a substitute for natural sand, characterised in that the ball mill is stopped and opened to take out the material to the material outletRefining of crushing sand as a substitute for natural sand, characterised in that the ball mill is stopped and opened for the material outflow, the opening is located at the bottom (outflow of the material by means of gravity)Refining of crushing sand as a substitute for natural sand, characterised in that a further opening is provided in relation to the material inlet for the material outletRefining of crushing sand as a substitute for natural sand, characterised in that the ball mill consists of metalRefining of crushing sand as a substitute for natural sand, characterised in that the ball mill consists of plasticRefining of crushing sand as a substitute for natural sand, characterised in that the ball mill consists of rubber and / or of rubber-like materialsRefining of crushing sand as a substitute for natural sand, characterized in that the ball mill is operated with auxiliary rounding materialsRefining of crushing sand as a substitute for natural sand, characterised in that rounding auxiliary material is used instead of metal ballsRefining of crushing sand as a substitute for natural sand, characterized in that the auxiliary rounding materials consist of metalRefining of crushing sand as a substitute for natural sand, characterised in that the auxiliary rounding materials made of metal have a geometry adapted to the crushing sand to be roundedRefining of crushing sand as a substitute for natural sand, characterized in that the auxiliary rounding materials consist of natural rockRefining of crushing sand as a substitute for natural sand, characterized in that the auxiliary rounding materials consist of the same rock as the crushing sand to be roundedRefining of crushing sand as a substitute for natural sand, characterized in that the auxiliary rounding materials consist of mineralsRefining of crushing sand as a substitute for natural sand, characterised in that the rounding auxiliary materials are adapted in grain size to the material to be roundedRefining of crushing sand as a substitute for natural sand, characterised in thatthe auxiliary rounding materials consist of harder material than the crushing sand to be roundedRefining of crushing sand as a substitute for natural sand, characterised in that further rounding devices (for example further mill types) can be used as long as the crushing sand is not ground but is rounded.Refining of crushing sand as a substitute for natural sand, characterised in that the installations can be constructed in different sizes, depending on the throughputRefining of crushing sand as a substitute for natural sand, characterised in that the material to be rounded is moved horizontally, depending on the plant used for roundingRefining of crushing sand as a substitute for natural sand, characterised in that the material to be rounded can be moved vertically depending on the plant used for roundingRefining of crushing sand as a substitute for natural sand, characterised in that air is used to support the rounding processRefining of crushing sand as a substitute for natural sand, characterised in that directed and moved air is used to support the rounding processRefining of crushing sand as a substitute for natural sand, characterised in that water is used to support the rounding processRefining of crushing sand as a substitute for natural sand, characterised in that directed and agitated water is used to support the rounding courseRefining of crushing sand as a substitute for natural sand, characterised in that the refined raw crushing sand, after leaving the rounding device, is washed to deblurten finesRefining of crushing sand as a substitute for natural sand, characterised in that the refined raw crushing sand after leaving the rounding device is sieved for division into individual fractionsRefining of crushing sand as a substitute for natural sand, characterised in that the method can be applied to all crushed natural sandsRefining of crushing sand as a substitute for natural sand, characterised in that the method can also be used for crushed recycling sandsRefining of crushing sand as a substitute for natural sand, characterised in that the selected process for rounding (=selection of the rounding device) is adapted to the starting materialRefining of crushing sand as a substitute for natural sand, characterised in that the factor of time must be taken into account in the processing of sands for roundingRefining of crushing sand as a substitute for natural sand, characterised in that natural sands can also be remachined with the chosen methodRefining of crushing sand as a substitute for natural sand, characterised in that refined crushing sand and natural sand can also be mixed to achieve a desired sand quality.Refining of crushing sand as a substitute for natural sand, characterised in that the rounded sand obtained by means of the described methods is also suitable for other purposes.