USRE502E - Improvement in the manufacture of sulphuric acxd - Google Patents

Description

UNITED ST TES PATENT OFFICE.

ALFRED MONNIER, OF CAMDEN, NEV JERSEY.

IMPROVEMENT IN THE MANUFACTURE OF SULPHUR IC ACI D.'

Specification forming part of Letters Patent No. 17,976, dated August 1i, 1817; Reissue N0. 50' dated I Octobcr 6, 1857'.

phurous acid (S0,) which is united with oxygen obtained by burning nitrate of potash or nitrate of soda. Sometimes sulphuric acid has been manufactured from metallic sulphuret or pyrites by heating it in close retorts and distilling over the sulphur, and afterward burning the sulphur so obtained with oxygen derived as in the other process; but in this wayonly thirty per cent. of the sulphur contained in the pyrites could be extracted. Another mode of treating pyrites was to burn the pyrites in a furnace furnished with a free supply of oxygen by the draft of a chimney, or by a blower. In this way only forty per cent. of the sulphur could be obtained in the form of sulphurous acid from the metallic sulphurets. A third mode of treating the pyrites or sulphuret was bydecomposing the sulphuret with a current of heated steam, and thus obtaining sulphureted hydrogen, (SH.) This was then collected in a gasometer and burned, forming sulphurous acid and water, which sulphurous acid .so obtained was oxidized, as above stated.

My improvement has for its object the manufacture of sulphuric acid from pyrites or any of the native metallic sulphurets, whether simple or compound sulphuretssuch as sulphuret of iron, sulphuret of copper, sulphuret of nickel, sulpheret of zinc, &c.and I treat the sulphuret as follows: If the native sulphuret of iron is employed, then I pulverize the sulphuret of iron and mix it thoroughly with from thirty-three to seventy-five per cent. of

its weight of either caustic soda, carbonate of soda, sulphuret of sodium, sulphate of soda, or with corresponding compounds of potash, or with sulphate of lime, sulphate of 'baryta, sulphate of strontia, or sulphate of iron. To

this compound a sufficient quantity of Water is added to keep it moist, and the mixture is. I retained in a state of moisture for eight or ten state and facilitates its combustion.

If it is desired to employ the mixture at once, a small quantity of water may be an ployed, sufficient to make the mass coherent,

' and this mixture is immediately made'into blocks. These blocks are burned in the same manner in which pure sulphuris ordinarlly burned, or they will burn better in a muffle, heat being supplied through a grate.

acid. W'hen caustic soda, sulphuretf of sodium, or sulphate of soda, carbonate of soda, or either of the corresponding salts of potash are employed, the residue, aiterlithe sulphur has been converted into sulphurous acld, W111 contain sulphate of soda, or a salt of potash and peroxide of iron, with some sulphateof iron. The sulphates can be dissolved in wa ter, and after concentration or evaporation to dryness they may be used again for the decomposition of a fresh quantity of sulphuret of iron or pyrites.

. The sulphate of iron, or thesulphates of other metals which are formed in more-or less quantity, are very advantageous, by reason of their reducing the quantity of nitrate of potash, nitrate of soda, necessary to be used in the format-ion of sulphuric acid.

Vhen the native sulphuret of iron treated contains sulphuret of copper, nickel, cobalt, 810., by applying moreor less heat those metals will remain in the residue as oxides, sulphates, or sulphurets, either simple or compound.

very little sulphate. If sufficient heat, but of short duration, is applied, the residue will contain the iron in the state of an-oxide, and

This compound burns very freely, and all, or nearly all,

If strong heatis'employed, oxides I will be produced in large quantity, but only the other metals as sulphurets, and only with a small quantity of sulphates; but by proper regulation of the heat the iron will be nearly all oxidized, an d the other metals will be in ostly converted into sulphates, Which,when dissolved in water, can betreated as may seem sulphate of iron is used in the first instance with the pyrites, the residue is peroxide of iron only; or if sulphate of lime, of strontia, or of ,baryta be employed, the residue will be sulphate of lime, of strontia, or of baryta mixed with peroxide of iron. If sulphuret of zinc or analogous sulphurets be employed, the abovementioned process is the same, except that when it is desired to obtain the oxide or sulphate more pure the sulphate of the metals under treatment might be substituted fO1\t-1l6 sulphate of iron. I

Instead of using caustic soda, sulphuret of sodium, sulphate of soda, or sulphate of iron, or either of the-salts of potash above named, in the solid state, in the first stage of the process these can be used in the state of a concentrated solution. The refuse or oxide of iron which remains after the process can be used as a paint. fEither of the salts above mentioned, and perhaps some salts not mentioned above,

could be used in the preliminary treatment of the'pyrites; but the sulphate of soda is the most advantageous and economical.

The advantage of my improved process, above described, is that all or nearly all the sulphur contained in the sulphuret of iron or othermetallic sulphuret can be converted into sulphuric acid, thus'effeeting a great economy in the manufacture of that acid. Instead of pulver-. izing the metallic sulphurets as found native, and mixing them immediately with either of the substances above mentioned, in the first instance, the native sulphuret might be partially' reduced by asimple roasting or fusion, and the residue treated by pulverizing and mixing it, as above described.

Having thus described my improved process, what I claim, and desire to secure by Letters Patent, is s, The process of preparing native metallic sulphurets by pulverizing them, and mixing them 'With'the substances above described, in order to extract all or nearly all the sulphur from them for the purpose of making sulphuric acid. I

ALFRED Montana.