Carbon black refers to engineered carbon nanoparticles that are fused together to form unique 3-dimensional aggregates. Carbon black, in its pure form, is a fine black powder. It is produced by partial burning and pyrolysis of oil residues or natural gas at high temperatures under controlled process conditions. Carbon black is different from charcoal. Carbon black has a complex particulate structure that is formed in a gas phase produced from fully pyrolyzed hydrocarbons at high temperatures. Charcoal is produced by the pyrolysis of wood or other carbonaceous materials at lower temperatures and is in bulk or milled powder form. Due to their structural and morphological differences, they have distinctly different performances.
Carbon black is usually made from hydrocarbon oils, e.g., refined coal tar or heavy petroleum oil, or natural gas. Hydrocarbons derived from recycled tires, and biomass, e.g., wood, etc., are gaining increasing attention as sustainable sources of feedstock.
Carbon black is a vital component in making many of the products we use every day strong, appealing, durable and safe. Some of these solutions include tires, automotive weatherstrip and belts, plastic parts, coatings, inks and sealants. For example, tires without reinforcing carbon black would not run over 100 miles. As a pigment, carbon black offers desired color strength for applications ranging from electronic enclosures to automotive coatings, and household appliances. Carbon black imparts UV durability to rubber and plastic goods to ensure their service life for a few decades. As an electrically conductive additive, carbon black renders insulative rubber and plastic materials antistatic, electrodissipative or conductive to provide safety and protection, and thereby reliability for mining, electronic packaging, and wire and cable applications, to name a few.
In principle, carbon black can be stored for many years in a dry, cool, and well-ventilated location. According to ATM D 8043 Standard Guide for Carbon Black — Shelf Life, “the shelf life of carbon black is defined as indefinite when stored in a manner that protects it from liquid water or high humidity environments. The only two properties of carbon black known to change over time are moisture and Iodine number. The moisture content can change over the short-term (weeks or months), depending on the ambient humidity and the surface area of the carbon black. Iodine number can change over an extended period (years) due to a slow increase in the oxygen content on the surface of the carbon black.” However, “the slight change in Iodine Number over an extended period does not affect actual surface area properties and in-rubber performance of the carbon black.”
Detailed guidelines may be found in carbon black’s safety datasheet (SDS) provided by the manufacturer or supplier, or in Carbon Black User’s Guide provided by ICBA (International Carbon Black Association).
Below are a few examples: 1) Avoid dust formation; do not breathe dust; provide appropriate local exhaust to minimize dust formation; do not use compressed air; 2) Take precautionary measures against static discharges; 3) Maintain safe work practices, including the elimination of potential ignition sources in proximity to carbon black dust, good housekeeping to minimize accumulation of dust, and appropriate exhaust ventilation design and maintenance to control airborne dust levels, etc.; 4) Handle in accordance with good industrial hygiene and safety practices.5) Use process enclosures and/or exhaust ventilation to keep airborne dust concentrations 6) Wear appropriate PPEs. e.g., respirators, masks, safety glasses or goggles, protective glove, and clothing, etc.
The industry has made tremendous progress in recovering carbon black for re-usage. One of the examples is to reclaim carbon black from post-consumer tires and reuse it for tires or other applications. After years of extensive research and development, Birla Carbon has introduced ContinuaTM Sustainable Carbonaceous Material (SCM) to make circularity a reality. Please visit https://www.birlacarbon.com/continua/ or contact a Birla Carbon representative for details.
The certificate of analysis (COA) provided by the manufacturer or supplier summarizes a carbon black product’s key properties, including iodine or nitrogen surface area, structure (OAN), cleanliness (sieve residue). that the COA may be used as a starting point to assess if the product meets quality requirements. Please contact a Birla Carbon representative for assistance.