USRE3151E - Improvement in the manufacture of artificial stone - Google Patents

Description

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"WILLIAM ILBOYLE, GF'BLADENSBURG, MARYLAND.

Letters Patent No. 82,202, dated September 15, 1868; untcdated September 7, 1868; reissue No. 3,151, dated October 6, 1868. t

IMPROVTIKENT IN THE MANUFACTURE OF ARTIFICIAL STONE.

TO AirL WHOM -IT MAY CONCERN: I Be' it known that I, WILLIAM K. BOYLE, oi" Bladensburg, in the county of Prince George, and State of' Maryland, have invented a new and useful Improvement in the Manufactureoi' Artificial Stone; and I do hereby declare the following a distinct description of the ingredients and of the process of preparing and compounding the same.

My invention relates tothe formation of artificial stone by the use of either the silicate of potash-or soda, in combination with sand, gravel; or any other insoluble earthy material, for forming the-mass or body of the stone, and subsequently submitting the mass thus formed to the action of a solution of nitrate of lime, whereby, by virthc of their chemical aflinities, the in'soluhle silicate of lime is formed throughout the mass, constituting the cementing propertythereof, after which the nitrate of potassa, the second product of the above-mentioned interchange in the stone, is to be washed out'by water, and, together with whatevei of said salt may remain in r the bath, to be utilized by chemical treatment and evaporation and chrystallization, as hereinafter described, to

form commercial saltpetre. In case silicate of soda be used, the resulting second product, the nitrate of soda to betreated in the" same way as the potassa salt.

I Y :Irocess.

- Mix intimately with well-dried sand, gravel, clay, or any other insoluble earthy substance, :1. suflicient. quantity of the soluble silicates of potassa or soda, in a semi-fluid form, and of a specific gravity varying as to the use for which the product is designed, say, from 1.300 up to the highest point of concentration, to form a plastic mass. These materials-tabs mixed by hand, or appropriate machinery. The proportions in the general .way to be about one part of soluble silicate to six or eight parts of sand, clay, gravel, 860- A small quantity of-' fine hydrhtc of limo or common slakcd lime, or carbonate of lime, or any insoluble substance, as finely-pulverized quartz, may be mixed with the compound, that every crevice or interstice may be effectually filled. The mass is then pressed into moulds of any desired form, said moulds being made of plaster of Paris, wood, iron, at

other suitable material. 7 After the mass is removed from the moulds, it is to be treated with a solution of nitrate of lime, either in a cold or hot'state, as may be desired, and either by washing or in a bath of said salt, as desired, when chemical interchange, by virtue of chemical aliinities, takes place, the nitric acid of the soluble nitrate of lime, having;

greater aliinity for the potassa or soda than vfor the lime, un'ites with the potassa or soda. forming the nitrate of potassa or soda, and the lime left free unites with the silicic acid, forming the insolublesilicate of lime, which is the cementing property throughoutthe stone. I

The nitrates of potassa or soda, being both soluble salts, are, easily removed from the stone by means of warm or hot water, they being washed out in solution, and the stone, thus freed from salt, has only to be dried to be ready for use. v y 1 When the original bath of nitrate of lime-refuses to work longer, and it may be used until well-nigh exhausted f limc, it is to be treated with carbonate of potassa or carbonate of' soda, to precipitate any lime remainingin the solution, when the fluid remaining, together with the washings of the stone, likewise so treated, is to be evaporated to a chrystallizable point, when nitrate of potassa or saltpetre or nitrate of soda will form.

These salts,=being oi'considerable commercial value, and .the' quantity ecpnomized in the large scale of manufacture being large, can be either sold in the market, or used asia source of nitric acid, to form the nitrate of lime,- and thus a continuous supply of nitrio'aoidcan be kept-up, and in either case, by ,sale or reuse, the cost of the stone will thereby be reduced very low. I

The stone thus formed will withstand all the usual atmospheric tests, and is not disintegrated. by frosts nor dissolved by the acids in common use, and may, by using an exhaust during the indurating proce be m de a hard as granite. v

For dsmp or very exposed sitnatioiu, the surface of the stone thus made might be advantageously coated, first, with a soluble silicate, and then brushed with the nitrate of lime, tbat'the silicate of lime may be deposited his the surface-pores, and, after again being washed'well, will be well-nigh impervious to water.

I am well aware that silicates of potassa and soda have been used with two other salts of lime, viz, chlo ratef of calcium' and saocharate of lime, to form artifieiehstone. Such a composition forms no part whatever of my invention, butthc use of the nitrate of lime, in the way described, by which it is economised and utilised, as set forth, "forming either a continuous process of man ufacture of nitrate of lime, or the nitrates of potash and soda. I I

This nitrate of lime has never, to my knowledge, been used or claimed tor this purpose, its first cost being so expe nsiye as to preclude entirely its use, but my method, by which the nitric acid is recovered, as set forth, and by which the cost of production of stone i's very much lowered, I regard-as entirely new.

By m'y process a much better an'd more reliable stone is produced than any ether method now known, for the resulting nitrate formed-in the body 'of the stone, is so much more soluble than the saltformed by any other process of manufacture new known, tbat it is much more readily washed out, whereas there exists an objection to forms of artificial stone, because of .the clogging of the pores of the stone by a salt not so readily or entirely yielding to the soluble'action of water, which salt, remaining in the stone, renders-it almost worth-. -less.- This objection is entirely met by mymethod, and, further, the discoloration of the surfaces of stone made by other-methods, by eflloresoenoe, lte.,'caused byundecomposed salt, or salt not washed out, does not take place in stone made by-mymothod.

,What I claim as my discovery, and desire to secure by' Letters Patent, is l 1 The herein-described improvement in artificial stone, bywhich an insoluble silicate ot' liine' is formed, by

the double decomposition of tbe'silicates oi potassa' or soda and nitrate of lime, substantially as herein set forth.

2. The herein-described methodot' forming artifieial stone, by the use of an alkaline silicate and nitrate of lime, when the latter salt is recovers-land the washings treated in the manner described, so as to utilise the .acid element or recoverthe nitrates for the market. I I

3. The utilization of .all the salts left in the residual liquors, as herein described, whereby a continuous formation at nitrate of Roma or ends is kept up. V i

In testimony whereof, I have signed my name to this specification before twosnbseribing witnesses.

I WM. K. BOYLE- Witnesses: v

Enm. F. Brown, 1). P. Homownj