(1) Selection and layout of construction site. The site should be located in a remote area or a relatively small number of operators. A sand warehouse should be arranged. The warehouse should be sealed as much as possible to prevent dust from blowing by wind. The operation time shall be properly arranged to stagger the peak period, and the operation at night shall be selected as far as possible.
(2) Sand material selection. Garnet with low quartz content is used as the casting material instead of quartz sand to reduce the dust hazard. At present, garnet sand is mostly used, because quartz sand, river sand/yellow sand, copper ore sand (metal slag), etc. previously used have been prohibited from being used as sandblasting abrasives in China and many other countries and regions because of free silicon, harmful heavy metals, silicosis, pneumoconiosis, cancer and other hazards. As a natural non-metallic mineral, garnet sand blasting abrasive does not contain free silicon and toxic heavy metals, and it is non radioactive. Because the proportion of garnet sand is large (4.0-4.2), the sedimentation rate is fast, and there are six times of water washing during the processing of RZG garnet sand, so the dust will be very little, so there is no health or environmental risk during the sand blasting process. In recent years, most of the sand blasting is used garnet internationally.
(3) Selection of working climate and environmental conditions. Sand blasting for rust removal on the surface of steel substrate has certain requirements on atmospheric humidity, and sand blasting operation is also limited to windy weather to reduce the range of dust diffusion with wind.
(4) Key points of nozzle operation during operation. The nozzle shall be aligned with the surface or ground of the substrate before opening the nozzle valve. At the end of the operation, the valve must be closed before the nozzle leaves the substrate. The steel substrate shall be placed on the ground and shall not be suspended. The nozzle shall not be sprayed to the air or personnel.
(5) Waste recycling. At the end of the operation, the sand and dust deposited on the site must be cleaned in time. During the transportation of waste materials, three proof tarpaulins must be covered to avoid scattering or raising dust anywhere. Dust free does not affect the effect of sanding. The garnet sand is hard. For example, the iron aluminum garnet selected for RZG garnet sand is 7.5-8, second only to topaz, corundum and other gemstones, and higher than the commonly used sand blasting materials such as quartz sand, sea sand and river sand.
When encountering metal surface during sand blasting, garnet sand is not easy to break. Even after breaking, it will produce new particles with edges and corners that are similar to cubes. Therefore, the garnet dust-free sand blasting abrasive can be used repeatedly, generally more than 8 times, which is several times of siliceous sand (sea sand or river sand) and quartz sand. The relative cost of using it once is low.
