Walter Weldon

Walter Weldon, 1884

Walter Weldon (born October 31, 1832 in Loughborough , † September 20, 1885 in Burstow ) was an English chemist , journalist and publicist . His second son was Walter Frank Raphael Weldon , an English zoologist and biometrician .

life and work

Walter Weldon developed a method for the for the recovery of chlorine from hydrogen chloride and manganese dioxide resulting manganese (II) chloride to convert back into pyrolusite. The Weldon process named after him was first replaced by the Deacon process and later by the electrolytic production of chlorine by chlor-alkali electrolysis .

In 1854 he started as a journalist in London for The Dial , which was later taken over by The Morning Star . In 1860 he published the monthly magazine Weldon's Register of Facts and Occurrences relating to Literature, the Sciences and the Arts . He also edited the Weldon's Fashion Journal , Weldon's Patterns, and Weldon's Household Encyclopaedia . He also published knitting instructions through Weldon & Company in the late 1800s. Weldon's Practical Needlework and Weldon's Ladies' Journal (1875-1954) appeared around 1888 .

In 1877 he was elected a member ( Fellow ) of the Royal Society of Edinburgh .

Weldon process

In the first step, manganese dioxide reacts with hydrochloric acid to form manganese (II) chloride with evolution of chlorine:

{\ displaystyle \ mathrm {MnO_ {2} +4 \ HCl \ longrightarrow MnCl_ {2} + Cl_ {2} +2 \ H_ {2} O}}

The resulting manganese (II) chloride is mixed with lime water and , when exposed to air, calcium manganite is formed , which can be returned to the process:

{\ displaystyle \ mathrm {2 \ MnCl_ {2} +3 \ Ca (OH) _ {2} + O_ {2} \ rightarrow CaO \ cdot 2 \ MnO_ {2} +3 \ H_ {2} O + 2 \ CaCl_ {2}}}

The resulting calcium manganite reacts with HCl as follows:

{\ displaystyle \ mathrm {CaO \ cdot 2 \ MnO_ {2} +10 \ HCl \ rightarrow CaCl_ {2} +2 \ MnCl_ {2} +2 \ Cl_ {2} +5 \ H_ {2} O}}

The MnCl ₂ can be recycled, while the CaCl _{2 is} a by-product and has to be disposed of.

Web links

Chemistry: basic knowledge for engineers , by Gerd Blumenthal, Dietmar Linke, Siegfried Vieth (as Google Book)

Individual evidence

^ Fellows Directory. Biographical Index: Former RSE Fellows 1783–2002. (PDF file) Royal Society of Edinburgh, accessed April 21, 2020 .

personal data
SURNAME	Weldon, Walter
BRIEF DESCRIPTION	English chemist and publicist
DATE OF BIRTH	October 31, 1832
PLACE OF BIRTH	Loughborough
DATE OF DEATH	September 20, 1885
Place of death	Burstow

[1] Fellows Directory. Biographical Index: Former RSE Fellows 1783–2002. (PDF file) Royal Society of Edinburgh, accessed April 21, 2020 .