Coloant lubricants (CL) refer to compulsive element of the majority of technological processes of material treatment by cutting and shaping. Lathe work, milling, drilling, grinding and other processes which include cutting of steel, iron, nonferrous metals and alloys, non-metal construction materials as well as stamping and rolling of metals are all characterized by high static and dynamic loads, high temperatures, impact that the material being treated on the cutting tool, and by metal-shaping and rolling equipment.
Under such conditions, the main function of coloant lubricants is to reduce temperature, cutting forces, wear of cutting tool as well as stamping presses and shaping rolls; to ensure satisfactory surface quality. Moreover, the coloant lubricants are to meet hygienic, ecological and other requirements and to feature a complex of anti-corrosive, detergent, antimicrobial as well as other characteristics. The application of coloant lubricants in machining and shaping operations enables to enhance equipment power, improve finish quality of treated surface as well as to reduce surface roughness and product failure. Furthermore, application of coloant lubricants provides better working conditions and decreases the number of working operations.
A range of coloant lubricants in advanced industrial countries includes industrial oil lubricants, cutting fluid fractions with additives, water soluble oils (forming coarsely dispersed emulsions in water) and other compounds forming microemulsions or transparent solutions in water. Petroleum oil (usually containing anti-wear and extreme pressure additives) and their 3% …10% emulsion refers to the most widespread coloant lubricants.
BM technology of spent coloant lubricants treatment reaches at the same time 3 main targets:
There are examples of BM technologies implementation for spent coloant lubricants treatment on the units with ceramic and polymer membranes. The comparative characteristics are given below.
Considering comparative data, we performed further works in terms of application of BM technologies for treatment of spent coloant lubricants using only ceramic membranes.
Flow condition rate of coloant lubricants which are used in the process of cold forming, being treated by MF (UF) membranes as well as the flow diagram of BM process are both shown in figure below.
Permeate refers to the process water, quality of which enables it to be disposed into the sewage network as well as into surface-stream flows. Water recycling in technological cycles is the most promising.
Concentrate can be either recovered by recycling or taken for further concentration and recovered by burning.
It should be noted that BM technologies in the process of oil-containing wastewater treatment may be used ONLY at the stage of FINAL TREATMENT/POST-TREATMENT of wastewater. It is not efficient to use membrane unit on the first stages of treatment, as under such conditions it should be cleaned too often. Moreover, the construction of membrane units imposes meaningful constraints on the treatment of water containing abrasive particles such as sand.
Flow diagram of BM treatment process of oil-containing wastewater is shown in figure below.
BM units with ceramic MF membranes may be used for the treatment of oil-containing water in the following technological cycles:
Permeate refers to the process water, quality of which enables it to be disposed into the sewage network as well as into surface-stream flows. Water recycling in technological cycles is the most promising.
Concentrate is burned together with oil-containing waste of primary treatment cycle (oil separator, flotation unit, etc.)
The appearance of stratal water products having been treated on BM unit with ceramic MF membranes is shown below.