Abrasive Types Explained
Coal slag is a black, glass matrix alumina-silicate which is produced when wet bottom boiler power plants burn pulverized coal. The bottom ash is kept in a molten state until it is tapped and introduced to water. The water quenches the molten slag and instantly vitrifies it producing the raw glassy slag which Ensio Resources recycles and beneficiates through its processing facility to produce a variety of value added products for market. It has the optimal hardness, density, and particle shape to provide for an exceptional silica free blasting abrasive, roofing granule, non-skid, and sealcoating surface material.
Coal slag is not to be confused with fly ash or other forms of coal combustion byproducts which have completely different physical and chemical characteristics.
Copper slag is a by-product of copper extraction by smelting. During the smelting process, molten slag is tapped off into fresh running water which instantly vitrifies the slag producing a black glass matrix with angular and shiny characteristics. The material is very similar to coal slag but exhibits higher densities.
Crushed Glass is manufactured from 100% recycled container glass. The manufacturing process crushes the glass and strips away contaminants and waste by-products. The material is then sized and screened for abrasive blasting. This makes Crushed Glass an environmentally friendly product which serves to reduce glass which would otherwise be needlessly sent to landfills.
For optimal performance, Ensio Resources recommends the following nozzle and grit sizes for your projects. Download a printable sheet with all the information you need here.
Choosing the correct nozzle size for your selected material and compressor is essential to ensuring the quality of the completed job. As a general rule, nozzle size should be 3 times the size of grit size used, minimum. For compressor output using Patriot Blast Coal or Elite, use between 90 and 110 PSI. For blasting with our Crushed Glass, we recommend between 80 and 90 PSI. Recommended nozzle size by grit size and Patriot Blast product line are below:
Grit sizes can be easily visualized: 1240 grit is comparable to raw sugar, 2040 is similar to granulated sugar, 3060 can be compared to table salt, and 4080 is as fine as baby powder. In order to create an optimal surface for coating adhesion, abrasive material is used to create a desired profile on the substrate. The depth profile of the pattern is measured in thousandths of an inch, or mils. Recommended Patriot Blast product and grit sizes to achieve a desired profile (within mil spec) are below:
Coal & Elite (Iron Silicate)
1240 2.0-4.0 mils
2040 1.5-3.0 mils
3060 1.0-2.0 mils
4080 0.5-1.5 mils
1230 2.0-4.5 mils
2030 1.5-3.5 mils
3060 1.5-3.0 mils
4070 0.5-1.5 mils
ESTIMATING MATERIAL USEAGE (DRY BLASTING)
If you are using a #4, or ¼”, nozzle, approximately 560lb of material should be expended per hour. This equates to approximately nine 60lb bags of Patriot Blast (coal slag) or Patriot Blast Elite (iron silicate/copper slag).
With a #5 nozzle, you will use approximately 900lb of material per hour, or approximately fifteen 60lb bags of Patriot Blast (coal slag) or Patriot Blast Elite (iron silicate/copper slag).
IS YOUR NOZZLE WORN? AN EASY TEST
Find a drill bit in a size equivalent to the nozzle orifice (i.e. #4 nozzle = ¼” orifice, look for a ¼” drill bit). Insert drill bit into nozzle – if the fit is snug, the nozzle does not require replacement. If the drill bit is loose or falls in, it’s time for a new nozzle tip!
The following is a very general explanation of why Low Free Silica abrasives are important to choose over those with free or crystalline Silica:
Silica occurs in three major forms: Amorphous, Microcrystalline, and Crystalline. The form of silica that needs to be scrutinized for health concerns is the "crystalline silica" also known as "free silica." Crystalline silica which causes silicosis occurs as quartz, cristobalite, or tridymite and as such it is the levels of these specific forms of crystalline silica that need to be determined and scrutinized. Regular sand usually contains very high concentrations of these dangerous forms and this is the reason why such stringent safety measures are required if an operator does choose to use a regular Silica sand.
Silicon and Oxygen make up around 75% of the earths crust, so geologically speaking, SiO2 is actually an exceedingly common compound and can be found virtually everywhere. The first line of the Patriot Blast MSDS showing SiO2 (Silicon Dioxide) levels of 41-53 % refer to non crystalline or free Silicon Dioxide (ie- amorphous silica) and as such this is not the harmful compound that is associated with Silicosis.
ERI is committed to producing the highest quality Silica free products and we are confident that you will find that our products will meet and exceed your expectations.
EPA Beneficial Use Compliance
ERI Coal Slag products are the smart, safe alternative to many other types of blasting abrasives and other industrial minerals. The EPA has produced a draft proposal which seeks to properly classify and impose regulation on only hazardous CCP’s. Beneficial Use productsare described in the following way by this proposal:
“Beneficial Use of Coal Combustion Products (CCPs) means the use of CCPs that provides a functional benefit; replaces the use of an alternative material, conserving natural resources that would otherwise need to be obtained through practices such as extraction; and meets relevant product specifications and regulatory standards (where these are available). CCPs that are used in excess quantities, placed as fill in sand and gravel pits, or used in large scale fill projects, such as for restructuring the landscape, are not considered beneficial uses.”
ERI Coal Slag products are clearly beneficial-use-compliant in every way, and due to ERI’s commitment to safety, product quality, and the environment, shall continue to be for many years to come.
The EPA draft proposal can be downloaded in PDF form at the following link: http://www.epa.gov/epawaste/nonhaz/industrial/special/fossil/ccr-rule/ccr-rule-prop.pdf
Patriot Blast (COAL SLAG): Click here to download (PDF).
Patriot Blast Elite (COPPER SLAG/IRON SILICATE): Click here to download (PDF).
Patriot Blast Glass: Click here to download (PDF).
Black Velvet Roofing Granules: Click here to download (PDF).
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