Specialty Inorganics & Chemical Intermediates

Lithium carbonate is the usual lithium source for LFP (lithium iron phosphate) and lower-nickel NMC cathodes. High-nickel NMC and NCA cathodes are normally made with lithium hydroxide monohydrate, because it reacts at lower sintering temperatures, roughly 700 to 800 °C, and avoids releasing CO2 and leaving residual carbonate, which harms cycle life. Lithium hydroxide is also the lithium source for lithium 12-hydroxystearate greases.

In a vapour-absorption chiller, water is the refrigerant and a concentrated lithium bromide solution is the absorbent. LiBr is strongly hygroscopic and non-volatile, so it absorbs the water vapour formed in the evaporator; the diluted solution is then heated in the generator with steam, hot water or waste heat to drive the water off again, replacing a compressor. Commercial solutions usually carry a corrosion inhibitor chosen to the chiller maker's specification.

N-Bromosuccinimide (NBS) and N-chlorosuccinimide (NCS) are solid, easily weighed sources of reactive halogen. NBS is the standard reagent for allylic and benzylic bromination (the Wohl-Ziegler reaction), bromohydrin formation and bromination of activated aromatics. NCS chlorinates activated aromatics and other substrates and acts as a mild oxidant, for example in the Corey-Kim oxidation. Both spare the chemist from handling elemental bromine or chlorine gas.

Para tertiary butyl catechol (PTBC, 4-tert-butylcatechol) prevents styrene polymerisation by trapping peroxy radicals, which form when monomer radicals react with dissolved oxygen. Without oxygen, PTBC cannot do this and protection is lost, so inhibited styrene should keep a small amount of dissolved oxygen in storage. Styrene is commonly held above about 10 to 15 ppm PTBC, and the level is checked during storage because the inhibitor is consumed over time.

All are amorphous silicon dioxide, but they are made and used differently. Silica gel is a hard, highly porous granule or bead with a large internal surface that adsorbs moisture, so it is used as a packaging desiccant, for gas drying and as chromatography media. Precipitated and fumed silicas are fine powders used as reinforcing fillers in rubber, anti-caking and free-flow agents, matting agents in coatings, and abrasives or thickeners in toothpaste.

Methyl bromide is an ozone-depleting substance controlled under the Montreal Protocol, and its remaining permitted uses are mainly quarantine and pre-shipment fumigation of grain, timber and export packaging. Because its sale and use are regulated in India, we supply it only to buyers who hold the licences the law requires, packed and labelled as hazardous goods with the manufacturer's COA and SDS.