Volume 08 (1864) (474 pages)

70 The Wining and Scientific ress, {For the Mining and Scientifle Press.] THE MINERS’ LABORATORY. Assaying Copper Ores, It is of great importance tbat every copper prospector should be acquainted with the best method for ascertainiug the percentage of copper, in copper ores. Indeed it is our impression tbat every copper mine sbould be provided with a small laboratory for testing their ores, particularly when we kuow that such a laboratory could be ficted up at a cost not exceediug $200, with a further expeuse of only about 50 cents upon each assay for chemicals, ete. By following this, companies would save themselves much anxicty about their minerals, instead of having a bypotbetieal value for the time being. So soon as a mineral is discovered they would he able to aseertain its value, iustead of nursing it in their pockets, talking about its merits, of whieh tbey know nothing, until at last they actually believe it to be extraordinarily rieh; and when they come to San Francisco it is tested perhaps by some of our assayers and a return made: of “no copper,” or perhaps only a slight trace of one or two per cent. At this they are greatly disapointed; tbe assayer must surely have committed a blunder, and ere they are satisfied, perhaps the rock will bave to traveled the whole round of our offices. All this will eost a considerable sum. We will now deseribe the apparatus necesary:— First, a small balance that will carry about 500 grains in each pan, and turn distinctly with one-fiftietb part ofa grain. Six small flat bottomed glass flasks, to bold from four to six ounces; two nests of beakers, the largest to hold about six ounces; six four-ounce glass funnels; a filtering stand to hold about four filters at a time; six half-ounee glass porcelaiu crucihles; two glass wasb bottles to wash filterers and precipitates; a package of filtering paper; aniron pestle and mortar; a sieve about 100 boles to the inch; a common stove to boil your solutions upon; a bottle of bydrocblorie acid; a bottle of nitric acid and several strips of good sbeet iron, eut up into small pieces about one ineh square. — HOW TO ASSAY SULPHURETS OF COPPER NOT CONTAININO ARSENIC, ANTIMONY, JERCURY OR BISMUTH. ‘We will now suppose a miner bas a copper ore for assay. In the first place pulverize the ore; rougbly at first, if the sample he large; after so doing, mix it well; spread it on a elean floor, take a little from all parts, mix well what you so obtaiu, aud pulverize very fine, so that tbe whole will pass through your sieve of the fineness above described; mix well again, spread ou a paper and weigh out very carefully in your balance, 25 grains of tbe ore, taking a little, to make up yonr weight, from different parts of your fiue ore. Plaee the weighed ore earefully in one of your small glass bottles; add to it about one-quarter of an ounee of nitric acid, and then a few drops of hydrochloric acid; place your flask on your stove; it would be better if you would cover your stove with about one-half ineh depth of fine sand, and place the bottle on this, keeping up a slow and steady fire. Allow your bottle containing the sifted ore and the acid to remain on the stove, boiling slowly, until you perceive small yellow globules swimming on the surface of the liquid. Should you observe that the solutiou is nearly evaporated, before the yellow globules appear, add a few drops more of nitrie acid. Evaporate to dryness, heat the dried mass slowly, and allow to cool very gradually. Remove your flask from the stove; allow it to cool perfectly; theu add a few drops of hydrochloric acid; just sufficient to moisten the whole; allow it to stand for about oue-half bour; then add a few more drops of bydroebloric acid, heat slowly; add hot water to the amount of two ounces; remove the bottle and liquid from the stove, and filter the solution; add hot water, in small portious at atime, on your filter, after the eopper solution has gone through, until neither the water will taste acid; nor the paper in the funnel, After haying doue this take one of tbe strips of sbeet iron and clean tbe same with a file or sand paper notil it is perfectly bright; when this is done place the bright strip of iron in your filtered copper solutiou; then place the whole on the sand, on yonr stove; heat gently but not to boiling. The copper will by tbis method deposit itself in the shape of metallic copper on the iron, but may easily be removed. When your liquid appears almost white, take a bright piece of iron with your fingers and dip one end of it in the solution; if it does not become colored to the slightest extent with copper, the whole of that metal has been precipitated. If such is the case remove the beaker containing the copper fromthe stove; mix your solution with a small feather—a feather from the wing of aduek. Any copper that may adhere to the iron must be removed by means of the feather. Allow the liquid to stand for a few momeuts, tap the glass slightly against the table, in order to collect all the eopper into one part of the glass; deeant the liqnid now from the metallic copper; add more hot water, shake up by means of your featber; allow precipitate to subside; then pour off water again; continue adding water and decant until the water will not taste acid; when this is done remove your copper hy means of your wash bottle to one of the small porcelain erucibles. Allow the eopper time to subside; pour off the water, and dry the eopper; theu ent a, hole in the lid of your teakettle, as a convenient way, say one ineh in diameter, place the erucible containing the eopper in this hole; boil the heaker in the teakettle, and the stcam thus generated will dry your mnetallic eopper. It is important, bear in mind, that you should not beat this precipitated metallic copper above the boiling point of water, if you do your result will not be accurate. When you think it is dry, remove the crucible and allow it to remain at rest in a bot place fora few moments, but not in o hotter place than the boiling point of water. The object of this last drying is to remove any condensed steam that may remain on your crucible. After drying this, weigh the erucible and metallic copper together; note the weight, place the crucible again as at first, on tbe teakettle and keep it boiling for a few moments; remove the erueible as before, and dry it; reweigh; if it weighs the same as at first, all right; if uot dry again, and so on until you ohtain two weighings preeisely the same. When you obtain this, throw your copper away and weigh the crucible; deduct the weight of the erueible from that of the erucible aud metallie eopper, and multiply the remainder by four, and tbe product will he the percentage of eopper, in the ore examined. Take, for example 25 grains of ore:— Weight of crucible and substan Weight of crucible alone. 486.42 grains. we Weight of metallic copper. a Tbus you have 6.20 grains of eopper in 25 grains of ore. Then to obtain the percentage:— 25: 100 :: 6.20 : 24.80 per cent. copper, oF, 6.20 x 4 = 24.80 per cent. copper. When carbonate or oxide of copper, not contaiuing any sulphurets of eopper, has to be assayed for eopper, the proeess is alittlesimpler. We pulverize the ore as at first; but instead of using nitrie and hydrochloric acid, we simply use hydroehloric. Keep the ore at a boiliug poiut; dilute, when all action bas ceased, with hot water, and filter, without evaporation, and precipitate as before by means of @ bright pieee of iron. With the exception of the above operation, the whole is done precisely as the. method already discribed. We sball in future numbers give the method to be employed for assaying all the various deseriptions of copper ana silver ores. x Oregon Iron.—The editor of the Oregon Demoerat bas been shown two butcher knives, made by Albany blacksmitbs, from the ore of tbe Tualatin irou mines. Iron is said to exist in that locality in abundance. A forge has been erected, and is uow in ogeration, and the construetion of a rolling mill aud other machinery for the manufacture of iron from: the ore, is in eontemplation. A Reese River Mansion, Dear reader, if you are tbe owner of numerous feet in the rich land of silver, be not startled hy the above caption, through fear that some lucky wight bas stolen the marcb, and reared, previous to you, 2 substantial castle upon some of the magnificent “ Hights of San Francisco,” but read with caudor of the sublime abode occupied by one of the best and happiest of God’s noblemen—an ex-typo and practical operator in Reese River mines. The extract here given is from a private letter, and was never intended to meet the “ vulgar gaze” of the pnblic:— “TI went to work putting up a country residence for myself, in which I am now liviug, as happy and independent as an Irisb lord. The style of architecture adopted is a sort of eross between the Arabic and Hibernian—the roof being formed from a tent, and the walls being made hy digging a hole in the banks aud leaving the sides three or four feet high, ou the top of which partial walls have been laid with stoues, eapped with logs, to whieb the eanvas is nailed. ‘The rear wall is nothing but a bank of earth, and the front of the house is formed of poles, staudiug on eud and sunk into the ground about,a foot, ‘The furniture is luxurious, and as my dining-room, kitchen, parlor, library and bed-room are all furnished alike, a deseription of one will answer forall. The door, facing the east, is closed by a hanging blanket. As you enter the door, to your right is my couch, spread with Oriental magnifieenee, composed of four uprights, four horizontal picces, two large guuny sacks, a mattrass eomposed of a donkey’s breakfast, two pair of heavy Mission blankets, anda pair and a halt of lighter ones. In the eorner, beyond the bed, stauds a saek of sngar, and a large box containing sundry articles of food. South of these and ranged against tbe wall, stands the water bucket, tea-pot, eoffee kettle, pots, ete. and in the south-west corner stands my stove—used alternately for cookiug aud warming. Strung up over head are hams and bacon, and under the eouch are flour, beans, efc., in profusion. The “New Chemical Agent in Warfare,” An item has been going the rounds of the papers for some weeks to the effeet that an Evglish chemist proposes to carry up iu balloons, a quautity of “chloride of nitrogen ”’ and drop the same into an euemy’s eity or eamp. So powerful is this terrible compound that two or three earboys of it dropped into a city or fortress, it is thought, would completely destroy the saine, its inhabitants as well as its defences. Even if such terrible destruction should resnit, of whieh there are, at least, grave doubts, it may not have oceurred to the ingenious projector that to earry out bis projeet would require the absolute sacrifice of eaeb individual aeronaut eonnected with the enterprise. A detonation sufficient to accomplish such a sudden and wide spread ruin, would prove sure destruetion to tbe frail aerial vessel aud its occupauts. An ordinary four or six pounder even, discharged at any point nearly over whieh a balloon is passiug, produees a most fearful effect npon tbe machine. We reeollect well, some twenty-five years ago, when ballooning was first attempted from Boston Common, that on the first ascension a complimentary salute was fired from a couple of four pounders. On the seeond ascent it was especially requested that the salute should be dispensed with, in consequenee of the extremely unpleasant, if not dangerous effeets produced by the detonation. If danger was apprehended from such a slight concussion, what must be expected from an explosion so terrific as to destroy an entire eity? Perhaps, however, patriots could be found who would be willing to saerifiee themselves for so important an advantage to their country. Men can be readily found who will rush eagerly upon a battery when the chances of eseape are not more than one in twenty or thirty, but few, we apprehend, can be found who would walk deliberately and without the excitement of battle or ‘‘ the charge ” to meet an inevitable death, and that so terrible as would attend the catastropbe we are supposing.

70 The Wining and Scientific ress, {For the Mining and Scientifle Press.] THE MINERS’ LABORATORY. Assaying Copper Ores, It is of great importance tbat every copper prospector should be acquainted with the best method for ascertainiug the percentage of copper, in copper ores. Indeed it is our impression tbat every copper mine sbould be provided with a small laboratory for testing their ores, particularly when we kuow that such a laboratory could be ficted up at a cost not exceediug $200, with a further expeuse of only about 50 cents upon each assay for chemicals, ete. By following this, companies would save themselves much anxicty about their minerals, instead of having a bypotbetieal value for the time being. So soon as a mineral is discovered they would he able to aseertain its value, iustead of nursing it in their pockets, talking about its merits, of whieh tbey know nothing, until at last they actually believe it to be extraordinarily rieh; and when they come to San Francisco it is tested perhaps by some of our assayers and a return made: of “no copper,” or perhaps only a slight trace of one or two per cent. At this they are greatly disapointed; tbe assayer must surely have committed a blunder, and ere they are satisfied, perhaps the rock will bave to traveled the whole round of our offices. All this will eost a considerable sum. We will now deseribe the apparatus necesary:— First, a small balance that will carry about 500 grains in each pan, and turn distinctly with one-fiftietb part ofa grain. Six small flat bottomed glass flasks, to bold from four to six ounces; two nests of beakers, the largest to hold about six ounces; six four-ounce glass funnels; a filtering stand to hold about four filters at a time; six half-ounee glass porcelaiu crucihles; two glass wasb bottles to wash filterers and precipitates; a package of filtering paper; aniron pestle and mortar; a sieve about 100 boles to the inch; a common stove to boil your solutions upon; a bottle of bydrocblorie acid; a bottle of nitric acid and several strips of good sbeet iron, eut up into small pieces about one ineh square. — HOW TO ASSAY SULPHURETS OF COPPER NOT CONTAININO ARSENIC, ANTIMONY, JERCURY OR BISMUTH. ‘We will now suppose a miner bas a copper ore for assay. In the first place pulverize the ore; rougbly at first, if the sample he large; after so doing, mix it well; spread it on a elean floor, take a little from all parts, mix well what you so obtaiu, aud pulverize very fine, so that tbe whole will pass through your sieve of the fineness above described; mix well again, spread ou a paper and weigh out very carefully in your balance, 25 grains of tbe ore, taking a little, to make up yonr weight, from different parts of your fiue ore. Plaee the weighed ore earefully in one of your small glass bottles; add to it about one-quarter of an ounee of nitric acid, and then a few drops of hydrochloric acid; place your flask on your stove; it would be better if you would cover your stove with about one-half ineh depth of fine sand, and place the bottle on this, keeping up a slow and steady fire. Allow your bottle containing the sifted ore and the acid to remain on the stove, boiling slowly, until you perceive small yellow globules swimming on the surface of the liquid. Should you observe that the solutiou is nearly evaporated, before the yellow globules appear, add a few drops more of nitrie acid. Evaporate to dryness, heat the dried mass slowly, and allow to cool very gradually. Remove your flask from the stove; allow it to cool perfectly; theu add a few drops of hydrochloric acid; just sufficient to moisten the whole; allow it to stand for about oue-half bour; then add a few more drops of bydroebloric acid, heat slowly; add hot water to the amount of two ounces; remove the bottle and liquid from the stove, and filter the solution; add hot water, in small portious at atime, on your filter, after the eopper solution has gone through, until neither the water will taste acid; nor the paper in the funnel, After haying doue this take one of tbe strips of sbeet iron and clean tbe same with a file or sand paper notil it is perfectly bright; when this is done place the bright strip of iron in your filtered copper solutiou; then place the whole on the sand, on yonr stove; heat gently but not to boiling. The copper will by tbis method deposit itself in the shape of metallic copper on the iron, but may easily be removed. When your liquid appears almost white, take a bright piece of iron with your fingers and dip one end of it in the solution; if it does not become colored to the slightest extent with copper, the whole of that metal has been precipitated. If such is the case remove the beaker containing the copper fromthe stove; mix your solution with a small feather—a feather from the wing of aduek. Any copper that may adhere to the iron must be removed by means of the feather. Allow the liquid to stand for a few momeuts, tap the glass slightly against the table, in order to collect all the eopper into one part of the glass; deeant the liqnid now from the metallic copper; add more hot water, shake up by means of your featber; allow precipitate to subside; then pour off water again; continue adding water and decant until the water will not taste acid; when this is done remove your copper hy means of your wash bottle to one of the small porcelain erucibles. Allow the eopper time to subside; pour off the water, and dry the eopper; theu ent a, hole in the lid of your teakettle, as a convenient way, say one ineh in diameter, place the erucible containing the eopper in this hole; boil the heaker in the teakettle, and the stcam thus generated will dry your mnetallic eopper. It is important, bear in mind, that you should not beat this precipitated metallic copper above the boiling point of water, if you do your result will not be accurate. When you think it is dry, remove the crucible and allow it to remain at rest in a bot place fora few moments, but not in o hotter place than the boiling point of water. The object of this last drying is to remove any condensed steam that may remain on your crucible. After drying this, weigh the erucible and metallic copper together; note the weight, place the crucible again as at first, on tbe teakettle and keep it boiling for a few moments; remove the erueible as before, and dry it; reweigh; if it weighs the same as at first, all right;

if uot dry again, and so on until you ohtain two weighings preeisely the same. When you obtain this, throw your copper away and weigh the crucible; deduct the weight of the erueible from that of the erucible aud metallie eopper, and multiply the remainder by four, and tbe product will he the percentage of eopper, in the ore examined. Take, for example 25 grains of ore:— Weight of crucible and substan Weight of crucible alone. 486.42 grains. we Weight of metallic copper.. a Tbus you have 6.20 grains of eopper in 25 grains of ore. Then to obtain the percentage:— 25: 100 :: 6.20 : 24.80 per cent. copper, oF, 6.20 x 4 = 24.80 per cent. copper. When carbonate or oxide of copper, not contaiuing any sulphurets of eopper, has to be assayed for eopper, the proeess is alittlesimpler. We pulverize the ore as at first; but instead of using nitrie and hydrochloric acid, we simply use hydroehloric. Keep the ore at a boiliug poiut; dilute, when all action bas ceased, with hot water, and filter, without evaporation, and precipitate as before by means of @ bright pieee of iron. With the exception of the above operation, the whole is done precisely as the. method already discribed. We sball in future numbers give the method to be employed for assaying all the various deseriptions of copper ana silver ores. x Oregon Iron.—The editor of the Oregon Demoerat bas been shown two butcher knives, made by Albany blacksmitbs, from the ore of tbe Tualatin irou mines. Iron is said to exist in that locality in abundance. A forge has been erected, and is uow in ogeration, and the construetion of a rolling mill aud other machinery for the manufacture of iron from: the ore, is in eontemplation. A Reese River Mansion, Dear reader, if you are tbe owner of numerous feet in the rich land of silver, be not startled hy the above caption, through fear that some lucky wight bas stolen the marcb, and reared, previous to you, 2 substantial castle upon some of the magnificent “ Hights of San Francisco,” but read with caudor of the sublime abode occupied by one of the best and happiest of God’s noblemen—an ex-typo and practical operator in Reese River mines. The extract here given is from a private letter, and was never intended to meet the “ vulgar gaze” of the pnblic:— “TI went to work putting up a country residence for myself, in which I am now liviug, as happy and independent as an Irisb lord. The style of architecture adopted is a sort of eross between the Arabic and Hibernian—the roof being formed from a tent, and the walls being made hy digging a hole in the banks aud leaving the sides three or four feet high, ou the top of which partial walls have been laid with stoues, eapped with logs, to whieb the eanvas is nailed. ‘The rear wall is nothing but a bank of earth, and the front of the house is formed of poles, staudiug on eud and sunk into the ground about,a foot, ‘The furniture is luxurious, and as my dining-room, kitchen, parlor, library and bed-room are all furnished alike, a deseription of one will answer forall. The door, facing the east, is closed by a hanging blanket. As you enter the door, to your right is my couch, spread with Oriental magnifieenee, composed of four uprights, four horizontal picces, two large guuny sacks, a mattrass eomposed of a donkey’s breakfast, two pair of heavy Mission blankets, anda pair and a halt of lighter ones. In the eorner, beyond the bed, stauds a saek of sngar, and a large box containing sundry articles of food. South of these and ranged against tbe wall, stands the water bucket, tea-pot, eoffee kettle, pots, ete. and in the south-west corner stands my stove—used alternately for cookiug aud warming. Strung up over head are hams and bacon, and under the eouch are flour, beans, efc., in profusion. The “New Chemical Agent in Warfare,” An item has been going the rounds of the papers for some weeks to the effeet that an Evglish chemist proposes to carry up iu balloons, a quautity of “chloride of nitrogen ”’ and drop the same into an euemy’s eity or eamp. So powerful is this terrible compound that two or three earboys of it dropped into a city or fortress, it is thought, would completely destroy the saine, its inhabitants as well as its defences. Even if such terrible destruction should resnit, of whieh there are, at least, grave doubts, it may not have oceurred to the ingenious projector that to earry out bis projeet would require the absolute sacrifice of eaeb individual aeronaut eonnected with the enterprise. A detonation sufficient to accomplish such a sudden and wide spread ruin, would prove sure destruetion to tbe frail aerial vessel aud its occupauts. An ordinary four or six pounder even, discharged at any point nearly over whieh a balloon is passiug, produees a most fearful effect npon tbe machine. We reeollect well, some twenty-five years ago, when ballooning was first attempted from Boston Common, that on the first ascension a complimentary salute was fired from a couple of four pounders. On the seeond ascent it was especially requested that the salute should be dispensed with, in consequenee of the extremely unpleasant, if not dangerous effeets produced by the detonation. If danger was apprehended from such a slight concussion, what must be expected from an explosion so terrific as to destroy an entire eity? Perhaps, however, patriots could be found who would be willing to saerifiee themselves for so important an advantage to their country. Men can be readily found who will rush eagerly upon a battery when the chances of eseape are not more than one in twenty or thirty, but few, we apprehend, can be found who would walk deliberately and without the excitement of battle or ‘‘ the charge ” to meet an inevitable death, and that so terrible as would attend the catastropbe we are supposing.