US874907A - Mining salt. - Google Patents

Description

No. 874,907. PATENTED DEG. 24, 1907i H. FRASGH.

MINING SALT.

PPLIOATION FILED NOV. 13. 1899. RENBWBD MAY 20, 1907.

' 3 SHEETS-SHEET l.

wit/Leona No. 874,907. PATENTED DEG. 24, 1907.

H. FRASCH.

MINING SALT.

APPLIUATION FILED Nov. 13. 1899. RENEWBD MAY 20,1907.

3 SHEETS-SHEET 2.

' nuenfoz N01 874,907. PATBNTED DEG. 24', 1997. 11. PRASGH.

MINING SALT.

APPLIGATION FILED 11011.13. 1899. RENBWBD MAY 2o. 1907.

3 SHEETS-SHEET 3.

l 111ml, muuu UNITED sTATEs PATENT OFFICE.

HERMAN FRASCH, OF CLEVELAND, OHIO, ASSIGNOR TO THE UNITED 'SALT COMPANY, OF

CLEVELAND, OHIO, A CORPORATION OF OHIO.

MINING` SAUF. l

Specication of Letters Patent.

Patentedl Dc.' 24, 190W;

Application led November 13, 1899. Serial N0. 73.6.8421. ,Renewed May 20| 1907. Serial No. 374.725.

This invention relates more particularlyy tothe recovery of common salt from a natural (usually subterranean) deposit, by the aidL of an aqueous'solution, which is formed in -said deposit and is thence removed to the surface of thel ground, and from which the salt is separated; but it extends to the recovery of any saline-or non-saline substance soluble in water from a natural deposit. Y v

It has long been customary in this art, in order to form such solution, to introduce water at ordinary temperature into the saltbed or deposit; but in a concurrent application (No. 705,604, filed February 16, 1899), I have described and claimed (among other things) a process in which unsaturated brine at su eratmospheric temperature is introduced lnto the salt-bed in order tov become saturated, and in which the brine, still above atmospheric temperature,I is on removal from said bed subjected to a partial Aeva oration at the ex ense of the heat-stored t erein, with or wit out the aid. -o heat from anl outside source or sources; By this partial evaporation, salt is precipitated, and the unvaporized (residual) brin-e is reduced in temperature. The salt is collected for sale or use; and the residual brine is'heated and diluted for return tothe salt bed.

There are advantages -inavoiding a resort to other.` heat than that 'which is in the brine from the salt deposit previous to its removal-.therefrom, even in aid of the evaporation -at they expense Aofthe-"stored heat; but if resort -be not had to such outside heat, then the evaporation removes so small a fraction of the water present that the unsaturated brine Which is formed by the heat- Wise-the volumef ofl residualbrine above ground would increase, which is not desirable' after a pro er working volume has been se-f cured. W ere. the .cavity inthe 'deposit is large, no diiiiculty is presented by the use of. 1

brine so nearly saturated but I have discovered that itssolventaction is lso slow as to` impair its .usefulness for newly ,opened deposits, or for those in which the cavitiesfare comparatively small. l

In the present invention, :evaporation .by

heat from another source or sources 1s.re sorted toin aid oftheheat in the brine at `the time of its removal from the deposit;- but by utilizing a circulationof residual brlineiabove 7C Y as hereinafter explained,Y inMconjunction' ground asa carrier'of the .additionalheat withithe introductlon--intothe` depositl or"V the aqueous solvent free from .salt yor less Ff nearly saturated therewith and .'(in. either case) at superatmospheric' temfpverature, not only can. the salt .be-recovered nr general :with advantageover. the old saltom deposits:-

mminglplgocess using. water fit-atmospheric temperature, andalsoover. a process w1tho'ut. such above-ground circulation althoughusing. tmosphric an. aqueous solvent of Tsui i temperature and free from sa t er less nearly'. saturated-therewith, but it'can also be lre-.

covered fromnewly opened deposits orsthose.

with comparatively. small cavities with vadvantage .over ya process in Iwhich allfthe r residual. brine is heated and diluted for.

return to the deposit and, in whi'ch-consesalt saturation hereinabove mentioned .f The: present invention extends, however, part, to Working deposits of any size of cavity `quently the unsaturated brine introduced into .thel deposit has the high percentage of (however large. or however small) by means of unsaturated brine of anystrengthjeven brine s'ovnearly saturated asthat which ob-l tains when the brine from theI salt bed is eva orated at the expense of the heat inthe sai brine before its removal from the` salt bed, Without the aid of heat from an eutsidesource; and when all the residual -brine from such evaporationis returned to theJ salt-bed;

In my before-mentioned application, ref-'- erence is madeto an above-groundv circula-l' tion of residual brine. as a carrier for heat, in connection Vwith the introduction in to the deposit of a heated aqueoussolutionicon- Y stored partly in the brine from the deposit and partly in the residual brine of the above ground circulation; this matter, wl 111e withm the general scope of certain claims of my said application, is s ecifically claimed herein; and as to it an any other matter `(if any there be) so claimed herein and re transfer of heat thereto through heat-conducting Walls from steam condensed by said transfer, and maintaining the supply of said brine by addition thereto of hotr rine from the mine, formed by the introduction into the mine of the hot Water of condensation from said steam. Thus not only are-both the latent and the sensible heat of the steam 'utilized in promoting the evaporation, but

the sensible heat is further utilized in 1ncreasing the yield of salt by enabling a given amount of water to dissolve and carry off more salt from the mine. The brine to be evaporated can (under Athis improvement) not only be that of an above-ground circulation (as above described) but it can also in whole or in art be any other suitable body of brine, as or example the brine in an open steam heated pan, or in a closed steam heated pan with the brine therein under atmospheric, sub-atmospheric or super atmospheric pressure.

A further improvement conslsts in heating a bod of brine, more especially a body of residua brine in circulation (above ground or through the mine), by means of the exhaust steam from another body of evaporating brine itself heated by steam, and maintaining the supply of both bodies by addition to each of hot brine from the mine formed by.

the introduction into the mine, with or Without residual brine, of the hot water of condensation from the steam which heats each of said bodies of brine (and which may in part be condensed directly in residual brine when this is introduced into the mine). When the circulation of residual brine is Wholly above ground it is heated by surface condensation of the steam; When all, or even if only\ a part, of the residual brine is circulated throu h the mine, it can be heated by surface con ensation or by direct (injection) condensation of the steam therein.- In any case however, under this improvement, water water from both is vaporize which is vaporized from brine obtained from the mine and which retains heat imparted to it for vaporization is returned again to the mine to take up a new supply of salt.

By an exposure of the brine of not too Great tem erature unsupported in small drops distrlbuted throughout a large room filled With an evaporation-promoting atmosphere, the residual brine of the circulating system can be obtained so far below 135 F., which is about the practical lower limit of working of a vacuum salt pan, and also about the temperature of the exhaust steam of a condensing engine, as t0 serve as a condens- 1ngl1qu1d for such pan or other steam-ylelding vacuum apparatus, the water of condensation of said vacuum steam to be introduced into the mine, with or without residual brine according to the inode of working. The combination of vacuum evaporation or other source of vacuum steam with la circulating evaporation system, and the supply to both systems of hot brine formed in the mine at least in part from the water of condensation of the vacuum steam, constitutes another of the said additional improvements.

Another additional improvement consists in raising the temperature of the residual brine circulating above ground by the surface condensation of steam in chambers jacketed o'r bathed by said brine, introducing the water from said condensation, at superatmospheric temperature, and with or Without a portion of the residual brine, into the salt deposit, removing the brine formed by the solvent action of the Water or the unsaturated brine on the salt in said deposit, separating salt by an eva oration of brine at the expense of heat storedp in the two supplies of brine, and uniting the two streams beforeV or after the evaporation. When the two streams are united before eva oration, the

indiscriminately; but vwhere the evaporation takes place before union, a part of the particular rine from the salt bed Will be evaporated, and the remainder of such brine will be added to the above-ground circulation, `a art of the brine of which will be evaporated a so.

In the accompanying drawings which form part of `this specification, Figure 1 is a diagram partly in elevation and partly in vertical section of a salt-mining apparatus or plant which may be usefully employed in carrying out the invention; Fig. 2 is a similar diagram partly in plan and partly in horizontal section on line C C of Fig. 1; Figs. 3

and 4 are detail views of one of the sprinklers preferably employed.; Fig. 5 is a diagram partly in elevation and partly section of a somewhat modified salt-mining apparatus or plant,also in accordance with the invention, but-with some of the improvements omitted, and Fig. 6 is a view ofthe evaporating chamber and vat of Fig. 5, in vertical section at ri im angles to that of Fig. and' with part o said chamber and vat broken awa 4 The evaporator for the rbrine-circulating system shown at the right of Figs. 1, 2 and 5 and in Fig. 6 is represented herein, to illustrate first an evaporator adapted for evaporation to be effected therein at the expense of heat stored in the evaporating brine, and second, an evaporator in which such evaporation can be carried on by the exposure to an evaporation-promoting atmosp ere of the eva orating brine unsupported in the form of r rops.

lf the advantages of an evaporation `by exposure of the evaporating brine in the form of drops unsupported, should not `be desired, other apparatus may be used in which evaporation can take place at the expense of the heat stored in the evaporating brine, Without the aid of said exposure. An open pan or series of openpans 1n a well ventilated building, with an ordinary supply pipe, or avacuum pan with a similar-sup ly 1pc and without a heating belt (or with a eating belt if the vapor tension in the brine chamber would be less than corresponds lwith the temperature of the entering brine) would serve as such ap aratus. Other known or suitable forms o evaporator-for evaporating at the exlpense of the heat stored 1n the brine or ot er liquid previous to the evaporation (with or Without exposurein drops) may be used.

5 shown are to exhibit y wayy of example suitable forms oi a closedevaporator and steam heaters respectively.. Other known or suitable forms of such evaporator and hea-ters may be used, also an open evaporao tor.

Referring to Figs. 1-4, the evaporator for the brine circulation consists, as shown, of

a chamber 21 -in the form of alarge room,

supplied with air through the ducts 23 by4 V5 the air-inducting fans, 24, andy provided with sprinklers in the form of nozzles 26 (seeFigs. 3 and 4.) with spatter plates 27 in front of their jet orifices.y 28. The air escapes at the top of the chamber. The' .o sprinklers are mounted, .at opposite sides of the chamber 21, on horizontal pipes which receive brine from the supply pipe w, through the horizontal branches 251 and the upright branches 250. The pump 8-8 ,5 delivers the brine through the pipe g, the surface condensing steam heater r, the pipe 808 the surface condensing steam heater 8 and the pipe fw. It should be delivered into the eva orating chamber 21 under a pressure of om about twenty` to thirty pounds to the square inch, through jet orifices 28 which vmay be about a uarter inch in diameter; so that the jets are roken by striking against the splatter plates 27 into small drops of brine, w 'ch are exposed closed heaters the' temperature .may be The closed 'eva orator and heatersl vat.

unsupported in the slowly rising current of air in the chamber 21. The brine may have a higher or a lower temperature; but one of about 145 F. is a good average. With above the boiling point of the brine; fbut such superheating ofthe brine lintroduces diliculties; so that it is preferred not exceed the boiling point of the brine. The brine exposed unsu ported in small drops toan T5 atmos here o so muchvlower-vapor tension thant e brine (supposing the latter at say 145 F.) is rapidly evaporated, so that-during the passage of the drops throu h the atmosphere of chamber 2-1 a consi erable percentage (say upwards of three r cent.) of the water may be evaporate and the brine correspondingly lowered (sayiupwards of thirty degrees Fahrenheit) inrternperature. Under these conditions the evaporation proceeds faster than the precipitation of the salt in the -brine drops and the resultds a supersaturated solution of brine with partic es of a fine salt therein. So vfar as the present invention is concerned the nature .e0 of theA roducts is immaterial, so -long as salt is obtained b the eva oration; andfthe conditions can t erefore .varied as desired; only a large percentage `ci evaporation is desirable, and when .thefresidual brine, as explained below, is toghe used to condense vacuum ste-am, lthecooling caused by the evaporation should be suiicient to reduce the temperatureof=the brine (not'too hi h when injected) to a suitably low dgree. 1100 elow the sprinklers 26--27= at theilooro the chamber 21 is a vat 3l, divided-as shown into compartrnentsby.a partition v32 (Fi .2) and provided with an= overflow 33by wich the brine'enters the trough 212. -The sait .11.05 liberatedlin the brine drops, and other sait precipitated out of the-brine as it stands in the vat 21settles to the bottom 310- of the From this it couldn-be fished or raked out, mechanicallyv orby hand in .the manner :1110 in which salt is removed from'the ordina A open pans; butas shown, there isto-eac compartment of the vat a draw off 35 which' is opened when the salt has .accumulated to y the desired ,depth and through which-the T15 mother brine and salt .are removed. lhe brine flows of itself into the-conduit 36, -tob'e thereby conducted into` the pit -39 trom which it is-removed by the pump 398vandfdeliveredthrou h the pipe 399=to1the trough M120 212 above re erred to. The--salt-iszwashed out by a stream of brine from hose .attached to the hose plug 38 which is-su plied 'with brine for the supply pipe w tlirough -=tl1e branch pipe 380. The same -or a similar #1.25 stream carries the salt down the conduit 536 into the pit 39 for which it can-be-"removed by an elevator (not shown) forany desired treatment.

l Practically it isconsidered expedient to v1R30 separate the salt into grades by sifting; and Y the coarser particles can be ground if desired. These things, including the mode of and means for removing the salt from the vat 31 are outside of the present invention. The waste brine from the pit 39 can be pumped into the trou h 212 by pump 398 throu h pipe 399. t may also be observed that the brine from the vat 31 if not reduced by its repose therein from the condition of supersatu'ration to that of ordinary saturation, can be allowed further yto recipitate salt in other receivers before 1t is conveyed to the pump 88; and that to avoid difficulties of salt incrusting the pumps, the brine to be pumped can be heated with dry heat or by an injection of steam so as to be a little below saturation.

The heaters 1' and 8 are each composed of a vessel divided by tube sheets, with numerousv open ended tubes a between them, so as to form two chambers, one of .which includes the spaces inside the said tubes and the other the space outside the same, -as common in tubular heaters. As shown each of' these chambers has a valved brine inlet 71, and a valved brine outlet p, so that from pipe g or 808 the briie may pass through either chamber of the heater 1' or 8 according to which the passages h and p of the corresponding heater may be opened. Each heater has a valved steam inletf and a valved outlet g for the water of condensation. When the brine A is passing throu h one of the chambers of a heater (1' or 8) t e steam is admitted to the othel chamber; and at intervals the inlets and outlets are changed; so that any calcium sulfate which may have been gradually deposited on the tubes a (inside or outside as the case may be) while the brine is assing through or over the same, is gradua ly dissolveda oif when thev valves are changed and the steam is condensed in contact with the deposit. Should it be desired to useA heaters with the brine inlet and outlet for one chamber only, and the steam inlet and water outlet for the other chamber only, they could be used; and the deposits of calcium sulfate could be removed in the ordinary way (boiling with water and scraping).

The heater 8 has its chamber partly divided by two partitions 16 and 17 so that the brine and steam ass upward-throu h or over one half the tu es .a and then ownward through or over the other half; while in the heater1l they pass in one direction through or over all the tubes. An undivided heater such as 1' could be substituted if desired, for the partitioned heater 8, and conversely. As shown, the heater 1' is to be heated by vacuum steam from the closed evaporator t; and to aid in maintaining the vacuum (sub-atmospheric pressure) in said evaporator t above the brine therein, the condensed water outlets g of said heater 1' are made large order Y the bottom by dip to carry off also the uncondensed steam and are connected with an injection condenser supplied with cold water or brine through the injection pipe y and provided with a pipe z leading to an a1r pump (not shown) and with a water discharging pipe 10 sealed at ping into a cup and of sufficient Ilength for the hydrostatic column therein to counterbalance the `excess of pressure of the outside air due to the vacuum in the vessels 1' and t.

The closed evaporator (vacuum pan) t is provided between tube sheets with tubes a which divide its interior into two chambers, one composed of the spaces inside of said tubes together with the end compartments c and d beyond the tube sheets and the other of the space around said tubes. The dome e also forms' part of this chamber. Each chamber has a valved brine inlet h, a valved steam inlet f, a valved outlet l: for the exhaust (vacuum) steam given olf for the brine, a valved outlet l for withdrawing the salt which preci it'ates and settles, and a valved outlet g ibr .the water of condensation. One of the tubes a shouldbe of large diameter for the descent of the in the chamber which includes the inside'o the tubes and a similar passage should be formed in the chamber which surrounds said tubes a by omitting enough of these to leave a suitable passage. When one of the chambers is charged with brine, the other is receiving steam (say at atmospheric pressure) through pipe n from any suitable source (say a closed evaporator heated by steam of superatmospheric. pressure, or a non-condensing engine or other source) and the valves 'are changed from time to time; so that a chamber which has been charged with brine and Whose walls have become gradually incrusted with calcium sulfate from said brine, after an vinterval is supplied with steam, which condensing in contact with said wells gradually removes the incrustation while impart' heat through said walls (namely the sides of tubes a) to the brine which hasvbeen introduced into the chamber which was filled with steam before the valves were changed. Should it be desired to use a closed evaporator (vacuum pan) with-valved passages for the brine and its products (exhaust steam and salt) for one chamber. only, and with valved passages for the steam and its product (water of condensation) for the other chamber only, the same can be used; and the calcium sulfate can be removed'from time to time by boiling out and scraping the tubes a in the well known manner.

As shown the heater 8 is to be sup lied through the pipe-99 and one or`other o the steam inlets with exhaust steam `f:for the engine 858, at atmospheric pressure (212 E. temperature). This engine is to be taken as alrepresentative of whateverengine or en brine and salt 40 circulation, (third) the supplyl'rom a source and the Afans 24 and the e.

rlhewater ofl condensation from the heater r is conveyed by the pi e 400 provided with a trap atV the bottom an made of such vertical length as to support a column which will balwater o i it . pump'406 which discharges ance the excess of pressure of the air over the sub-atmospheric pressure (vacuum) in the heater r. The pipe 401 lreceives Water of condensation from the heater 1' through said vertical -fpipe 400; and it also receives the condensationy from the heater 8 (through the ipp' 402) 'and from the closed evaporator t t ough the pipe 403). The pipe 401 opens into the inlet pipe 424 of the t e water from said pipe 401 through the casing 40'] and well bore into the vunderground salt deposit 408. While in the said deposit, it speedily dissolves salt to a larger amount and all the more speedily on account of the elevated temperature of the water. Holding in solu tion the salt which it has dissolved in the deposit 408, it rises through the tubing 409 and is delivered by the pump 410 through the pipe 411 into the pipew which supplies the sprinklers 26-27 and through the pipe 412 to the closed evaporator t. As thus 'ar described therefore, there is first the circulation above ground of brine through the sprinklers 26-27, chamber 21, vatv 31, trough 212, pump 88, i e g, heater 1', pipe 808, heater 8, pipe w an t e branch pipes 251, 250 and 25 to the s rinklers 26-27, (second) the generationl om another body of brine, in one oithe chambers of the closed evaporator t, of vacuum steam which is supplied through the pipe w to the heater 1' for raising the temperature of the brine of the above mentioned not shown oi steam of (say) atmospheric pressure to the closed evaporator tfor boiling the aforesaid brine in the vacuum vchamber thereof, (fourth) the delivery from an engine 858 of exhaust steam of atmospheric pressure through the pipe 99 to the heater 8, (fth) the delivery to the underground salt deposit 408, through the pipes 400, 402 and 403, pipes 401 and 424 pum 406, casing 407 and well (or mine) bore of t e hot water from the con densation of steam which has become condensed in im arting its heat in the heaters'1n and 8 to the rine of said circulation and in the closed evaporator t to that oi said other body of brine, and'(sixth) the re lenishing of the said circulation and the sai other body' with hot brine formed in said deposit 408 by the water from said condensation of steam and supplied through the tubing 409, pump 410 an 'pes 411 and 412.

instead of replenishing the body of brine in the closed evaporator t directly from the brine which is'coining from the mine, all the -brine from the mine could be delivered into taken directly or indirectly from the mine,

-the relation of the temperature at which the brine is delivered into the evaporator t to that of the evaporating brine therein aiiects somewhat the role of the heat in said brine.

If the entering brine be no hotter than the said evaporating brine, then the heat in said entering brine promotes evaporation simply by lessening the quantity of heat required to raise it tothe evaporating temperature; but if it be hotter," then not only is no heat required to raise it to the evaporating temperature, but evaporation takes place at the expense of the heat previously stored in the entering brine, its sensible heat above the evaporatingl tem erature being converted into latent eat o the vapor or steam.

The brine from the mine (deposit 408) being at about the temperature of that from the heater 8. can most advantageously be introduced into the circulating brine on its way to the s rinklers 26`27 but'it could be introduce at any desired point. It could be eX- posed by a propriate sprinkles to the atmosphere of t e chamber 21 or of another like chamber before it is allowed tomingle with the `circulating brine. it is immaterial whether the Water of condensation descends through the casing and bore or through the tubing, (the brine in the latter case rising through the bore and casing or through a secon line of tubing).

rKhe heaters 414 and 415 lare formed each of an upright vessel provided with a steam inlet connected with piping 416 and 417 respectively at the bottom, with a brine inlet connected with pipes 418 and 419 respectively at the top, and provided with baffle plates 420 and 421 Within the vessel for ringing the steam and brine into intimate lsupplies vacuum steam to the heater 415.

The brine pipes 418 and 419 (as shown) are a branches of the pipe 422 which .is a branch of the discharge'pipe q of the vump 88. When therefore brineis umpedp into the tops 'of the vessels 414 an 415, it becomes heated (and diluted) in passing through said vessels by meeting and condensing the rising steam. The heated brine from the heater 415 could be pumped into the heater 414, (in place of the brine directly from the pipe g or 1n addition thereto); but as shown the outlet of heater 415 is connected with the inlet pi e 424 of the pump 406 by a long leg 423 (t at is by a ipe 423 of suicient vertical length for a co umn of water therein to balance the pressure of the air in excess of that inside of the heater 415). The leg or pipe ,423 is sealed at the bottom, being provided with an upward bend and entering the bottom of said inlet pipe 424. The outlet pipe 425 lof the heater 414 is connected with the' same pump inlet 424.

By o ening the proper stop cocks more or less of tliie residual brinerom the trough 21 2 -may therefore be forced by the pump 88 through pipe q," pipe 422, branch pipes 418 and, 419, heaters 414 and 415, pipes 423 and 425, pipe 424, pump 406, casing 407, well bore in continuation of said casing, deposit 408, tub` 409, pump 410, pipe 411, pipe w, and brahli pipes 251, 250 and 25 to the sprinklers 26-27. In passing through the heaters 414 and 415, the brine is raised in temperature partly by the heat of the vacuum exhaust steam from the closed evaporator t andpartly by the exhaust steam at atmospheric temperature from the engine 858, while at the same time the condensed water from said steam passes to the deposit 408 with the-brine which has been heated in condensingsaid steam, and forms brine to replenish the supply of brine in the circulation through the chamber 21, and also the body of brine in the closed evaporator t, the said circulation the underground salt deposit now including '408 instead o being outside said depositglike the circulation before described. The supply of replenis brine is further increased y the brine whio is formed in the deposit 408 by the Water of condensation from the close evaporator t and (if one or both the heaters r and 8 are running) by the brine which is formed by the water of condensation from one or both the heaters 1 and 8. By shutting oft' the heaters 1' and 8, the circulation can be establishedwholly through the underground deposit.

After the casing 407 has been driven, the well bored into a salt deposit, the tubing 409 inserted and the pipes connected with said .greatest rapidity possiblein dissol the mine (deposit 408) so increases that the s alt of importance; because the so vent llquid willwremain anyhow inthe deposit a suliclent time for a lower degree of dissolvthe ing capacity to produce saturation. In such case brine can with advantage be allowed to enter the mine (de osit 408) with thejwater of condensation. shown there is a branch pipe 430 by which brine from the pipe w can be admitted to the nletof the pump 406 in proper proportion to the size of the cavity, until nall the stop cock in the pipe w between the heater 8 and the junction of ipe w with the pipe 411 being closed, the w ole body of residual brine can be delivered to the pump 406 to be introduced into the deposit 408. 1t is however, ordinarily as advanta? geous to heat the brine by direct condensation of steam therein; provided the diluted brine can be supplied to the deposit 408; and for securing such advantages the residual brine, in any desired part or in whole, can be passed through the heaters 414 and 415.

It should be observed that when the brine circulation includes salt deposit 408, said brine can dissolve salt independent of its dilution by the water of condensation; because its temperature in the deposit will be higher than it was in passing through the pump 88; and the solubility of salt in water is increased somewhat by rise of temperature and that the amount of salt which is dissolved by reason of such higher temperature is clear ain since it can be deposited simply by the ref uction in the temperature which the brine undergoes in any event in the chamber 21 andv vat 31. There are, however, as before stated, some advantages peculiar to the above` ground circulation, which may, as in opening a newdeposit, more than compensate for this economy. l

Apart from the economy of etting rid of the troublesome removal of ca cium sulfate incrustation in the old way, there is also a certain special leconomy. surface condensing heaters and evaporators wherein the removal of the calcium sulfate incrustations is eiected b Vthe condensation of the steam in contact t erewith; because the water of condensation is then charged with calcium sulfate and when introduced into the deposit 408 does not dissolve so much as it otherwise would. Should it be desired to obtain exhaust steam at atmospheric or even at superatmospheric pressure from the evaporator t,

--this can be obtained by heating said evaporator with steam of appropriate superatmospheric pressure. In such case, the jet condenser :v and its appurtenances would be unnecess The c used-evaporator could of course be dispensed with, the corresponding heater (which uses the exhaust steam from the said evaporator) being dispensed with or being supplied'with steam from another source.

Referring to Figs. 5 and 6, the evaporator for the brine circulation is modified by placing the sprinklers 26-27 at the lower part of the chamber 21, and by placing the air intions could be used -without the other.` At 105 is a trough to catch the drip from the sloping sides of the partition 404, which forms" is the bottom of the air duct 23. The air enters at the windows 210 and is forced further inwards bythe deilectors 211. figures another form of surface condensin heater-is shown for the circulating brine; an

the closed evaporator, and the heaters using vacuum steam are omitted. When yusing surface condensing heating, the ump 128 delivers the residual brine from t e trough 212 through the pipe 110 into the left hand vessel of a series of three vessels, each containing a steamv drum 118 provided. with open ended tubes for the circulation of the brine throughthem. Bein somewhat raised in temperature, the brine ows through the pipe 119 into the middle vessel wherein it is still further heated, and then through the pipe' 120 into the right hand vessel, from which the hot brine is supplied throu h the pipe 117 to the pump 176 for de ivery through the pipes 177 .and 178 to the sprinklers 26-27 When desired however, the hot brine can be delivered from the pipe 117 through the pipe 129 and pipe 126 to the pump 406, for introduction into the salt deposit 408 through the casing 407- and well bore in continuation' thereof. From either or both the engines 858 (an additional one is shown at the left of Fig. 5 connected by pipe 909 with the pipe 99) exhaust steam at atmospheric pressure passes through the pipe 99 into the right hand drum 118 and' thence in succession through the other drums of the series, the steam being condensed as it proceeds. The drums are shown as connected at top by the pipes 122 and 124, for the passage of the steam, and at bottom by the pipes 123 and -125 for the passage of the water of condensation. This water .escapes by the ,pipe 126 to the pump 406 which discharges it into the deposit 408 with or without brine Afrom the pipe 129 or from the heater 415 or both, according to the manner ofworking.

The hot brine'from the mine (deposit 408) is delivered by the tubing 409 and the pipe 413 to the pipe 117 which supplies the pump 176 already'mentioned. At 115 is a safety valve for each engine. Between each of the pipes 113, which supplies the steam to the corresponding engine 858, and the pipe 99 or 909 for the exhaust steam is shown a byass 114 (found also in Figs. 1 and 2) for enab ing (onoccasion) live steam to be used for heat gor heating the circul ating brine by direct condensation, of steamtherein, a heater 414 is shown ofthe same construction as in Figs. 1 and-2. It is supplied with brine through pipe 417 from the pipe 110, and with steam through a pipe 416 from the pipe 909 which 858. The heated and diluted brine. passes I by pipe 425 to the pump 406. At 17.6 is'an escape for any uncondensed steam.l In my applications No. 736,842 and No.`

737,843, bot led November 13, 1899, I

have described and claimed im rovements, which (as so described) embody eatures that are .also described herein or that may lto some extent be suggested by`what is herein described. These features, however, concern onlyl the se aration of common salt or like substance om solution; while the claims hereinare all of them .limited to processes which include as essential coperating partsboth the formation of la solution' as specified in the respective claims and the separation of the common salt or like substance from the so formed solution. .The improvements clained in my said applications No. 736,842 and No. 736,843 can be usedand are designed (when so desired) to be used otherwise than in carrying out the processes claimed herein; which latter constitute, in fact, a distinct subject of invention.

i claim as my invention or discovery 1. The method of recovering salt or like substance from a natural deposit, by circulating outside of the deposit a stream of brine which is heated at a suitable point in the circulation, introducing an aqueous solvent liquid at su er-atmospheric temperature into the salteposit, removing the brine formed by the solvent action of said liquid still at super-` atmospheric temperature, separating salt out of solution lby an evaporatlon at the eX- pense of heat stored partly in the brine from 'the salt deposit and partly'in the brine circulating outside, and uniting the two brines, substantially as described. u

2; The method oi recovering salt or like substance from a natural deposit, by circulating outside of the deposit a stream of brine which is heated .at a suitable point in the circulation, introducing an aqueous solvent liquid at super-atmospheric temperature into the salt deposit, removingthe brine.

formed by the solvent action of said liquid still at superatmospheric temperature, sep'- arating salt out of solution by the exposure of the heated brine from the said deposit and 0f the outside circulation unsupported in drops to an evaporation-promoting atmosphere insuch manner as to eiect an evapo-4 ration at the expense ofheat stored partly in the brine from the salt deposit and partly in the brine circulating outside, and uniting the two brines, substantially as described.

3. The method of recovering salt or like substance from a natural deposit, by circulating outside of the deposit a stream of brine which is heated at a suitable point in thecir- 4culation, introducing an' aqueous solvent iic liquid comparatively free from salt and at superatmospheric temperature into the salt out of solution by an evaporation at substantially as described.

4. 1n recovering salt or like substance from anatural deposit by means of an aqueous solvent,. the improvement consisting in introducing Water com aratively free from salt after a working vo urne of brinehas been secured While the cavity in the de osit is comparatively small, and When t e cavity is arger introducing Water holding a larger proortion of salt in solution and formed of brine heated and diluted by direct condensation of steam therein, substantially'as described.

5. 1n recovering salt or like substance from a natural deposit by means of an aqueous solvent, the improvement consisting in introducing Water comparatively free from salt and at superatmospheric temperature When the cavity in the deposit is comparatively small, and when the cavity is larger introducing Water holding a larger proportion of salt in solution and formed of brine heated and diluted by direct condensation of steam therein, the salt being separated from the brine from the deposit by an evaporation at the expense of heat stored in the said brine previous to its removal from the de osit, and

the heated anddiluted brine intro uced into the deposit being residual brine from said evaporation, substantially as described.

6. The method ofrecovering salt or like substance from a natural deposit, as follows:

that is to say, When the cavity in the`deposit` is comparatively small effecting the surface condensation of steam by means of residual brine hereinafter referred toand introducing into the deposit the Water from said surface condensation at superatmospheric temperature, When the 'cavity in the deposit becomes larger heating and diluting residual brine hereinafter referred to by direct condensation of steam therein and introducing the soheated and so-diluted brine to said deposit, and in both stages removing the brine at superatmospheric temperature and separating the salt therefrom by evaporation at the eX- pense of heat stored in said brine previous to its removal from the deposit, so as to leave residual brine to serve for the surface or the direct condensation of steam hereinabove mentioned, the Water from the surface con densation and the heated and diluted brine from the direct condensation being both introduced if desired yet in such manner that the brine of greater strength be introduced When the cavity is larger, and the residual brine heated by surface condensation being subjected to evaporation as aforesaid' and united with brine from the deposit, substantially as described.

7. The method of recovering salt or like substance from a natural deposit, by raising the temperature of a stream of residual brine circulating outside of the deposit by the surface condensation of steam, introducing into the deposit an aqueous solvent at superatmospheric temperature composed of the Water from said condensation7 removing the brine from the deposit at superatmospheric temperature, separating salt by. an evaporation at the expense partly of the heat stored in the brine from the deposit previous to its removaltherefrom and partly of the heat stored in the residual brine by the said surface condensation of steam, and uniting brine from the deposit to the circulating stream of residual brine, substantially as described.

8. The method .of recovering salt or like substance from a natural deposit, by raising the temperature of a stream of residual brine circulating outside of the deposit by the surface condensation of steam, introducing into the deposit anaqueous solventI at superatmospheric temperature composed of the Water from said condensation, removing the brine from the deposit a-t superatmospheric tem erature, separating salt by the exposure of t e heated brine from said deposit and of the outside circulation unsupported in drops to an evaporation-promoting atmosphere in such manner as to efi'ect'an evaporation at the eX ense partly of the heat stored inthe. brine om the deposit previous to its removal therefrom and partly of the heat stored in the residual brine by the said surface condensation of steam, and uniting brine from the deposit to the circulating stream of residual brine, substantially as described. y

' 9. The method of recovering salt or like substance from a natural deposit, by raising the temperature of a stream of residual brine circulating outside of the deposit by the surface condensation of steam, introducing into the deposit an aqueoussolvent at superat mospheric temperature comparatively free from saltand composed ofthe water from said condensation, removing the brine from the deposit at superatmospheric tempera ture, separating salt by an evaporation at the expense partly of the heat stored in the brine from the deposit previous to its removal therefrom and partly of the heat stored in the residual brine by the said surface condensation of steam, and uniting brine from the de osit to the circulating stream of residual Ibrine, substantially as described.

10. The method of recovering salt or like substance from a natural deposit by raising the temperature of a stream of residual brine by the surface condensation of steam, introducing into the deposit an aqueous solvent l separatin salt at superatinospheric temaerature' composed partly of Water from sai condensation andy partly of .said residual brine, removin the rine from the deposit at superatmosp ericA temperature, and separating salt by an evaporation at the expense of heat in the brine from the deposit at the time of its removal therefrom, substantially as described.

11'. In recovering salt or like substances from a natural deposit by an aqueous solvent, the improvement consisting in introducing. Water com aratively free from 'salt after a working volp cured While the cavity in the de osit is comparatively small, and when t e cavity is arger introducing Water holdin a lar er proportion of salt in solution, su stantia y as described.

12. The method of recovering salt or like substance' from a natural deposit, by trans. ferring'heat to a body of brine through heatconducting wells from steam which is condensed to Water by such transfer. of its heat, introducing the said Water of condensation at superatmospheric temperature into-'the salt deposit, removin it therefrom after it has dissolved the sa t .in the deposit and While still at su eratmos heric temperature, om the st mentioned body of brine y an evaporation `which is promoted by the heat transferred thereto from the said steam, and replenishin the said body of brine by brine from'` said deposit,

. While. it still holds heat Which the said water of condensation retained from the said steam, substantially as described.

13. The method of recovering salt or like substance from a natural deposit, by evaporating a body of brine b heat transferred thereto through heat-con ucting Walls from steam` which is'condensed to water' by such transfer of its heat, evaporat'mg a second body of brine by heat ,transferred .thereto from the steam which arises from the first mentioned body of .brine and which is condensed to Waterb such transfer of its heat, introducing. the ot Water condensed lby each of said bodies of brine into the salt deposit, removing -the brine formed inthe de- .posit Joy .the dissolving action of said Water,

and replenishingboth-said bodies of brine by brine from said deposit While it stillholds heat which the Water of .condensation retained from the said steam, substantially as described. i,

e 14. The method ofrecovering salt or like substance from'a natural deposit, by evaporating a body of brine by heat trans erred thereto throu h heat-conducting walls from steam which 1s condensed to water by such transfer of its heat, circulating a second body ume of brine khas been se` of brine, transferring heat thereto at one point of its circulation from the steam which arises from the first mentioned body of brine and which is condensed .to Water by such transfer of its heat', eXposin the so-heated brine at another point of its clrculation to an evaporation-promoting atmosphere, introducing the hot Water condensed by each of said bodies of brine into 'the salt deposit, removing the brine formed in the deposit by the dissolving action of said water, and re plenishin both said bodies of brine by brine from sai deposit While it still holds heat which the Water of condensation retained' from the said steam, substantially as described.

15. The method of recovering salt or like mospheric temperature into the salt deposit,

and replenishing said body of brine in circulation with brine from said deposit While the latter still holds heat Which said Water of condensation retained from said vacuum steam, so that the evaporation of said first mentioned body o f brine is at the expense of the so-retained heat still present in the brine,

substantially as described.

16. The method of recovering salt orlike substance from a natural deposit, by transferring heat to a body of brine through heatconducting Wells by steam which is condensed to Water by such transfer of its heat, separatin saltfrom said brine by an evaporation W ich is promoted by the sotrans1 ferred heat, reversing the'respective positions of the brine and steam relative to .the said -heat-conducting Walls, introducing the water of condensation charged with calcium sulfate fromlthe incrustation left onsaid Walls by the brine into thedeposit of salt or like substance, and replenishing the said body of brine by means of the brine formed bythe dissolving action of the said Water in said deposit, substantially as described.

testimony whereof I aiiX my signature, i

in presence of two Witnesses.

' HERMAN FRASCH. Witnesses: w F. W. LOTHMAN,

J. C. UPDEeRovE.

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