Cutting fluid is a widely used industrial fluid, such as grinding without coreless grinding and grinding with various CNC machine tools. The cleaning effect on tools and workpieces! In the industry, cutting fluid is already one of the indispensable and widely used auxiliary products! The used cutting fluid will produce waste fluid. The waste fluid of the cutting fluid contains a large amount of mineral oil and various toxic organic substances, which are difficult to degrade through the natural environment. If it is discharged without treatment, it will cause great harm to the environment!
1. Waste liquid treatment of oil-based cutting fluid: oil-based cutting fluid generally does not smell bad. The reason for replacing the cutting fluid is mainly due to the chemical change of the cutting fluid, the increase in the amount of cutting chips, and the large amount of emulsified oil leaking from the machine for reasons such as water mixing, the following measures can be taken: 1) Improve the purification device of oil-based cutting fluid; 2) Regularly clean the chips of oil-based cutting fluid; 3) Prevent leakage of lubricating oil by overhauling the machine tool; 4) Regularly replenish cutting lubricating additives; 5) Heat to remove water, and add some cutting oil lubricating additives after precipitation and filtration to restore the quality and continue to use. The final waste oil treatment of oil-based cutting fluid is generally combustion treatment. In order to save resources, waste oil can also be regenerated.
2. Waste liquid treatment of water-based cutting fluid: The waste liquid treatment of water-based cutting fluid can be divided into four categories: physical treatment, chemical treatment, biological treatment, and combustion treatment. 1) Physical treatment, the purpose of which is to separate the suspended matter (referring to cuttings, abrasive powder, oil particles, etc. with a particle diameter of 10um or more) in the waste liquid from the aqueous solution. There are three methods as follows: degradation separation and floating separation using the density difference between suspended matter and water, filtration separation using Filter Material, and centrifugal separation using a centrifugal device. 2) Chemical treatment, the purpose of which is to treat fine suspended particles or colloidal particles (substances with a particle diameter of 0.001-10um) that have not been physically separated or to chemically treat harmful components in the waste liquid. Harmless substances, there are the following four methods: use inorganic flocculants (Polyaluminum Chloride, alumina sulfate, etc.) or organic flocculants (polyacrylamide) to promote the aggregation of fine particles, colloidal particles, etc. Condensation method; oxidation-reduction method that uses oxidants such as oxygen and ozone or electrolytic oxidation-reduction reaction to treat harmful components in the waste liquid; uses active solids such as activated carbon to adsorb harmful components in the waste liquid on the solid surface. Adsorption method to achieve the purpose of treatment; ion exchange method to achieve the purpose of treatment by ion-exchange of ionic harmful components in the waste liquid using ion exchange resin. 3) Biological treatment. The purpose of biological treatment is to treat organic matter (such as organic amines, non-ionic active agents, and polyols) in waste liquids that are difficult to remove by physical and chemical treatment. Its representative methods include bacteria addition Sludge method and scattered water filter bed method. The bacteria addition sludge method is to mix the bacteria addition sludge (microbial proliferation body) with the waste liquid for aeration, and use microorganisms to decompose and treat harmful substances (organic matter) in the waste liquid. The diffuse water filter bed method uses microorganisms to decompose and treat the organic matter in the waste liquid when the waste liquid flows through the surface of the filter material packed bed (filter bed) covered by microorganisms. 4) Combustion treatment includes direct combustion method and "evaporation concentration method" in which waste liquid is evaporated and concentrated and then burned.
