Abrasive materials are characterized by the ability of effective mechanical impact. With their help they remove impurities, remove deposits, clean surfaces from rust and paint. The working element, in fact, are abrasive granules, which can have different shapes and sizes. One of the types of such granules is abrasive dust, which may be of factory origin or may be the result of processing, waste, etc.
Abrasive dust general
Dust may have different characteristics and origin, but in most cases it is an undesirable product of processing metal and wood products. As a rule, abrasive powder is released during grinding and polishing work. Dust can be generated both in household surface treatment and in large volumes during operations on an industrial scale. In both cases, metal abrasive dust is generated as a result of the destruction of the main processing material. Most often, such wastes leave abrasive discs upon mechanical impact on the target surface to be treated. In this case, the dust is not always metallic - usually these are combined compositions that also include particles of abrasives from rocks.
Material Composition
Abrasive processing mainly involves ferrous metal products . This can be future parts for machine tools, and car components, as well as building materials. Iron forms the basis of any composition of such dust - about 30%. The second most commonly used content is aluminum oxide - alumina, although its qualities may also vary. The secondary constituent elements of abrasive powders include phosphorus, arsenic, nickel, manganese, chromium, etc. Much depends on which work surface the abrasive dust interacted with. The composition of the emitted mixture often includes elements of scale, rust and old coatings. Actually, to combat such deposits, the abrasive removal technique is often used.
Varieties of abrasive dust
The classification is based on several principles of separation of abrasive particles. In many respects they depend on the method of application of the processing material. For example, if a grinder with a nozzle in the form of a circle is used, then the resulting dust can be called silicon. The use of sandblasting machines, which initially use crushed abrasive grains, is also practiced. They may vary in size and shape, but their task remains the same - removing unnecessary coatings from the surface or ensuring the smoothness of the workpiece. The final product of processing in this case will be metal abrasive dust, but in a deformed form. It is important to note that, unlike silicon compounds, such dust can be used in further operations, as metal powders are used for grinding.
Specifications
Parameters and properties of the generated dust are determined by the conditions of operations and the materials used. For example, in work at machine-building enterprises, machines are manufactured that require high-precision finishing of surfaces to the desired geometric format. In this treatment, coarse dust is formed between the rolled billets and rolls, the sizes of which can vary from 5 to 10 microns. Usually it is obtained as a result of the evaporation of the same scale, which is about 20% by weight. On average, at such enterprises, dust emission is about 200 g per 1 ton of processed metal. If fire stripping is additionally applied, the volume of abrasive waste can increase significantly. When performing grinding operations on a smaller scale, the generated abrasive dust has a fine-grained character. Such dust particles have a diameter of 0.5-1.5 microns. But do not think that the allocation of small particles is safer than large ones. Firstly, the coarse fraction facilitates dust removal operations. Secondly, from a medical point of view, fine dust is more dangerous for the respiratory system. Now it’s worthwhile to examine in more detail the question of why it is necessary to deal with the free release of abrasive waste during processing.
Why is abrasive dust dangerous?
Without an effective dust extraction system, the production of metal dust will inevitably lead to its spread in the air of the working space. In such conditions, professional diseases of assembly fitters often develop. Such illnesses include pneumoconiosis, dust bronchitis, asthma, etc. The development of diseases can result from regular irritation of the lungs with abrasive particles from processing tools and from structural elements of the workpieces. Therefore, it is so important to initially organize systems that provide effective removal of abrasive dust directly in the working environment. Depending on the scale and working conditions, such systems are organized according to different principles. This can be a typical industrial vacuum cleaner connected to a grinder, and industrial ventilation.
Removal methods
Small abrasive elements from the material processed by means of surface grinding machines are usually collected and taken into special settling tanks. To do this, it is enough to think over the channel of the dust movement path. Most often, the problem is solved using planes wetted by water. Water veil carries powder into a sump equipped with a filter. Then again, already clean water flushes away portions of settling dust. For greater efficiency, it is possible to provide a drain channel with a ventilation system, which will prevent the accidental expansion of the smallest particles. In construction, they often use the already mentioned vacuum cleaner for abrasive dust, which at the moment of separation of the particles sucks them into a special container, preventing them from scattering. More productive abrasive control systems also involve the use of air flow. For example, an ejector, which is installed in the center of the separator housing, may be involved in the production of flows.
Conclusion
The production of abrasive particles is an inevitable phenomenon not only in grinding and polishing processes. Even typical metal cutting by “grinder” contributes to the formation of such elements. In this case, it is not always possible to provide a system due to which the abrasive dust would be removed automatically. Especially in domestic conditions when performing one-time repair operations, it is impractical to purchase the same vacuum cleaner specifically for this. In such cases, personal respiratory protection should be considered first. As for the protection of the surfaces of the premises, it will be useful to cover them with film before starting work. And it is mandatory to organize ventilation - at least through windows to the street.