The raw material oil for carbon black production is mainly composed of alkanes, aromatics, and asphalt, and its properties have a significant impact on the quality and yield of carbon black. The main requirement for raw material oil in carbon black production is a high content of aromatics and a low content of asphalt and impurities. The evaluation of raw material oil mainly considers its aromatic content, asphalt and colloid content, free carbon content, sulfur content, alkali metal content, moisture, density, distillation range and average boiling point, relevant indexes and hydrogen-carbon ratio, viscosity, etc.
I. The influence of raw material oil quality on the basic performance of carbon black
Since the raw material oil used for carbon black production is composed of various different types of raw material oils, the hydrocarbon composition of different raw material oils is different, and the process of cracking and the time required to produce carbon black are also different. The more mixed hydrocarbons there are in the raw material oil, the more complex the process of carbon black formation, and the greater the impact on the quality (properties) of carbon black, especially the uniformity of carbon black particle size and structure. It is difficult to achieve uniformity in carbon black particles and structure.
Mixed hydrocarbon raw material oil has a significant impact on the uniformity of carbon black particle size. The more types of mixed hydrocarbons, the worse the uniformity of carbon black particle size. Therefore, using a single hydrocarbon raw material oil and a raw material oil with a narrow distillation range is the best choice for carbon black production.
As mentioned earlier, aromatics in raw material oil are the main component of carbon black formation. Raw material oil with a high content of aromatics produces carbon black faster, with a shorter time, a uniform and high structure, and an increased yield of carbon black. On the contrary, when the content of alkanes in the raw material oil increases, the structure of carbon black decreases, and the yield of carbon black also decreases. Moreover, when the content of asphalt and colloid in the raw material oil is high, it can also cause a decrease in the structure of carbon black.
II. The influence of raw material oil quality on the sulfurized rubber performance of carbon black
The reinforcing effect of carbon black on sulfurized rubber depends on the basic performance of carbon black, namely, the particle size and structure of carbon black. If the particle size distribution of carbon black is uniform and moderate, the reinforcing effect of sulfurized rubber is good. Therefore, it is difficult to achieve the goal of improving the reinforcing performance of sulfurized rubber by producing carbon black with mixed hydrocarbon raw material oil and a wide distribution of distillation range.
The quality of raw material oil is closely related to the quality of carbon black. It not only has a significant impact on the production of carbon black but also is one of the most important factors determining the quality of carbon black.