Percy Carlyle Gilchrist (27 December 1851 – 16 December 1935) was a British chemist and a scientist who studied metals. He was also a Fellow of the Royal Society.

Life

Gilchrist was born in Lyme Regis, Dorset, to Alexander and Anne Gilchrist. He attended Felsted School and the Royal School of Mines. He contracted scarlet fever from his sister and became very ill. His father later caught the disease and died in November 1861.

He is best known for working with his cousin, Sidney Gilchrist Thomas, to develop the Gilchrist–Thomas process. This process became the standard method for making steel. It allowed the production of low-phosphorus steel from local high-phosphorus ores by changing the acidic process to a basic one. This made steel more affordable for British industry, as importing low-phosphorus ores was expensive. He and his cousin developed the process between 1875 and 1877. The process involved melting pig iron in a converter similar to the Bessemer process and exposing it to long periods of air blowing. The oxygen in the air removed carbon and other impurities. Adding lime at this stage caused the impurities to form a slag (dross) on the surface of the molten metal. A benefit of this process was that the phosphorus-rich slag became an agricultural fertilizer.

He or his family had him admitted to the private Holloway Sanatorium on 5 March 1899. He stayed there for nearly one year before being discharged into single care. He was noted for his unusual behaviors and his work as an inventor.

He was elected vice-president of the Iron and Steel Institute and became a Fellow of the Royal Society in 1891. He died in 1935. He married Nora, the daughter of Captain L N Fitzmaurice of the Royal Navy.