Consider emulsion performance indicators
Concentration: Emulsion concentration is a key factor. Generally speaking, the concentration of emulsion for hydraulic support should be determined according to the specific working conditions and equipment requirements. Usually the concentration range is between 3% - 5%. If the concentration is too low, the performance of the emulsion such as rust prevention and lubrication will be reduced, which may lead to increased rust and wear of hydraulic components. For example, in the underground environment of coal mines with high humidity, if the concentration of emulsion is lower than 3%, the column and other parts of the hydraulic support will easily show rust. And the concentration is too high, not only will increase the cost, but also may lead to too much foam, viscosity of the emulsion and other problems, affecting the normal work of the hydraulic system.
Stability: the stability of the emulsion includes chemical stability and physical stability. Chemical stability refers to the emulsion in the complex environment of the well to resist chemical reactions, such as resistance to oxidation, and mineral reactions in water. Physical stability mainly refers to the emulsion in the storage and use process, oil and water do not stratify the characteristics. A good emulsion should be able to remain stable in downhole temperature changes, long time standing and so on. For example, in some high-temperature mines, emulsions with poor chemical stability are prone to decomposition and deterioration, losing their proper performance.
Antirust performance: given the corrosive environment of the coal mine underground, the emulsion must have excellent anti-rust performance. High-quality emulsion can form a dense protective film on the metal surface of the hydraulic support, preventing the metal from being corroded by sulfides and chlorides in the mine water. The rust prevention ability of the emulsion can be evaluated through the rust prevention test, such as immersing the metal specimen in the emulsion for a certain period of time, and then observing whether there are rust spots generated on the surface of the specimen.
Lubrication performance: the hydraulic components of the hydraulic support have relative movement in the working process, which requires good lubrication. The lubricating performance of emulsion mainly depends on the additives in its formula. A suitable emulsion should be able to reduce the coefficient of friction between hydraulic components and reduce wear. The lubricating properties of emulsions can be tested in the laboratory with equipment such as a four-ball friction tester.
Selection according to the environmental conditions of the mine
Water quality condition: Water quality varies greatly from different water sources in coal mine underground. If the mine water is hard and contains more calcium and magnesium ions, its compatibility with hard water should be considered when selecting emulsions. Some emulsions may produce precipitation in hard water, affecting their performance. At this time, it is necessary to choose emulsions with strong resistance to hard water. In addition, if the water contains more impurities and microorganisms, it will also adversely affect the emulsion, and it may be necessary to pre-treat the water or select an emulsion with antibacterial properties.
Temperature conditions: Underground temperatures vary from mine to mine. In high-temperature mines, emulsions need to have good high-temperature resistance to prevent them from evaporating too quickly, deteriorating, or generating air bubbles at high temperatures. In low-temperature mines, emulsions should have good low-temperature fluidity to avoid solidification due to low temperature, resulting in the hydraulic system can not work properly. For example, in some cold winter coal mines in the north, it is necessary to choose the emulsion with lower solidification point.
Correct use method
Configuration process: The configuration of the emulsion should be carried out in strict accordance with the instructions. First of all, make sure to use clean water to avoid impurities in the water mixing into the emulsion. When adding emulsified oil, add it slowly and stir it thoroughly so that the emulsified oil is evenly dispersed in the water to form a stable emulsion. For example, use special stirring device, stirring time is generally not less than 10 - 15 minutes to ensure the quality of emulsion.
Storage management: The emulsion should be stored in a clean, cool and dry place. Avoid direct sunlight and high temperature environment to prevent the emulsion from deteriorating. The storage container should be well sealed to prevent dust, moisture and other impurities from entering. At the same time, pay attention to the shelf life of the emulsion, expired emulsion can not be used.
Regular testing and replacement: In the process of using hydraulic support, the emulsion should be tested regularly. The test content includes concentration, pH value, appearance and so on. If it is found that the concentration of the emulsion does not meet the requirements, or there is discoloration, strange smell or impurity precipitation, etc., the emulsion should be adjusted or replaced in time. It is generally recommended to conduct a simple appearance check of the emulsion at least once a week and a comprehensive performance test once a month.
Translated with DeepL.com (free version)
