ZHENGSHAN TECHNOLOGY

Electrode paste production is a critical process in the manufacturing of carbon and graphite electrodes for various industrial applications, such as steelmaking and electric arc furnaces. To ensure the quality of electrode paste, producers must adhere to strict quality control measures. Here, we discuss five key factors that are essential for controlling the quality of electrode paste.

1. Ash content: Ash content is the residual material of electrode paste when burned to constant weight at 850 ℃ -870 ℃. It belongs to the inorganic mineral category. If the ash content is too high, the electrical resistivity is high, the strength is poor, the power consumption is high, the electrode consumption is large, and it is prone to hard break accidents. Ash content is an important indicator, and the lower its value, the better.
2. Volatile matter: Volatile matter refers to the mass loss of electrode paste under isolated air heating conditions. Volatile matter is generally low molecular weight hydrocarbons, and the level of volatile matter has a significant impact on the quality of electrode paste. Excessive volatile matter, slow electrode sintering speed, large shrinkage rate after sintering, high porosity, easy oxidation, low strength, and prone to "soft break" or "hard break" accidents. The volatile matter is too low, the electrode sintering speed is fast, the adhesion is poor, the contact resistance between the electrode and the holder is high, and it is easy to cause "hard breakage" and "electrode ignition" accidents. The volatile matter of the electrode paste needs to be strictly controlled within a certain range.
3. Compressive strength: Compressive strength mainly refers to the limited compressive load per unit area of the sample after electrode paste baking, and is an important mechanical strength indicator. The electrode is subjected to tensile, compressive, bending, shear and other stresses in the mineral furnace. The compressive strength can indirectly reflect several other strength values and has the characteristic of being easy to test. Electrodes with low compressive strength have poor mechanical strength and are prone to "hard break" accidents during use.
4. Electrical resistivity: Electrical resistivity refers to the magnitude of the resistance per unit sample after electrode paste firing. Electrical resistivity is a physical quantity that represents the conductivity of an electrode. A small electrical resistivity results in low electrode resistance and low power consumption. There is an inverse relationship between the electrical resistivity and thermal conductivity of carbon products. Therefore, electrical resistivity is not only an electrical indicator but also a thermal indicator. Low electrical resistivity, high thermal conductivity, high temperature conductivity, low thermal stress value, good thermal stability, and electrodes are not easily broken by rapid cooling and heating.
5. Bulk density: Bulk density refers to the mass per unit volume of the sample after electrode paste firing. Bulk density is a physical quantity that measures the density of the macroscopic structure of carbon materials, characterizing the density and regular arrangement of particles in the electrode. High bulk density, low true porosity, denser electrode, higher mechanical strength, stronger antioxidant capacity, better thermal conductivity and thermal shock resistance.