IMPROVEMENTS IN EXTRACTING THE SULPHUR AND SULPHUROUS ACID FROM THE OXYSULPHURET OF CALCIUM, WHICH IS CONTAINED IN THE RESIDUES OR WASTE MATERIAL OBTAINED IN THE MANUFACTURE OF SODA
Year: 1862

page_text: PROVISIONAL SPECIFICATION left by William Schnell at the Office of
the Commissioners of Patents, with his Petition, on the 18th August
1862. A communication from abroad by Ludwig Mond, of Hessen
Cassel, Germany.
I, WILLIAM SCHNELL, of 63, Charlotte Street, Fitzroy Square, in the
County of Middlesex, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN EXTRACTING THE SULPHUR AND SULPHUROUS ACID
FROM THE OXYSULPHURET OF CALCIUM, WHICH IS CONTAINED IN THE RESIDUES OR
WASTE MATERIAL OBTAINED IN THE MANUFACTURE OF SODA," that the same is a
communication to me from abroad' by Ludwig Mond, of Hessen Cassel,
Germany, to be as follows:-
1. The waste material is moistened with water and then spread out upon
great hurdles superposed one upon another in the same manner as those used
in a common drying room. The principal condition is the unrestrained access
of air combined with some steam of water and carbonic acid if this is to be
found.
2. The material remains upon the hurdles for about two or three weeks but
never more than a month, after removing it from the hurdles it is washed out
(in an apparatus fit for the purpose) with water never exceeding a temperature
of 30 to 40 Centigrad (of Cilsius) and a solution of hyposulphite is thus
obtained. When this solution has been removed, the material is again spread

page_text: out upon the hurdles and after the required time washed out again till no more
hyposulphite will be found.
8. Treated in this way the residue or waste material acquires more weight
during their stay upon the hurdles, this augmentation of weight is equal to the
whole weight of the hyposulphite formed, it results therefrom that if the
waste material contains 5% of sulphur to be gained from the hyposulphite
the weight of the sulphur is equal to 6% of the primitive weight of the waste
material used, and after having repeated the above-named process twice we
have therefore obtained 12% of sulphur.
4. The hyposulphite of calcium thus obtained must now be decomposed,
this will be done by using muriatic acid in the following manner :-
5. The solution of hyposulphite is boiled in an iron boiler and while boiling
the muriatic acid is to be added by degrees and the solution kept boiling till
the sulphur is separated from the sulphurous acid which is then let off and the
sulphur will be found at the bottom of the boiler in a pure state.
5. If we wish to obtain sulphur alone the hyposulphite of calcium is evapo-
rated by heating till dry, and then distilled by heating in iron retorts, by thus
proceeding we obtain half the sulphur contained in the solution and the residue
remaining in the retorts contains a mixture of sulphite of calcium, sulphate
of calcium and sulphuret of calcium.
6. If we wish to obtain sulphurous acid only, the solution, when evaporated
as before, is to be heated in furnaces with an unrestrained access of air, and
half the sulphur which the solution contains is obtaining as sulphurous acid,
and the residue left in the furnace is entirely composed of sulphate of
calcium.