Show TESTING PLANT OF GENERAL engineering CO WRITTEN FOR THE MINING REVIEW BY E B HAYES metallurgical ENGINEER the ore testing plant of the general engineering gi company at salt lake city is probably the most complete plant of its kind in the entire united states this company of which which mr air J M callow is president and mr ernest gayford is superintendent with an expert staff of assistants is conduct conducting in some of the most thorough and far reaching tests that have been attempted along these lines the plant lem embraces braces two floors and basement of the company companas comp anys Is building on pierpont street including offices drafting room and the most complete equipment of all kinds for the determining of ore processes while the work of this company also embraces the design and supervision of m mi J construction and operation by far the most interesting work carried on is the actual testing of the ores from the data obtained by working tests of a lot of ore the mills are designed this does away with the rule of P 00 exterior general engineering companas Comp anys building thumb methods used in mill construction causing the failure of many mills the complex natures of the ores received require the most thorough testing and the work in this department is of a precision and thoroughness ough ness that can only be obtained with long practice the ore after sampling first passes through the main crushing plant consisting of a four inch by seven inch dodge crusher and twelve inch by twelve inch rolls at this stage it may be further reduced in size by passing through a three and one half foot huntington mill and a threefoot three foot hardinge tube mill or it may be elevated after passing through any of these machines from the elevator the ore may be thoroughly screened and classified for ordinary table and jig practice the tailings returned for further grinding if found advisable or may be subjected to cyanide amalgamation or other tests the cyanide equipment consists of one five ton leaching tank one agitating tank with hendryx agitator four gold solution tanks three stock solution tanks two zinc boxes four sumps bumps one kelly filter press and one dorr classifier the plant is so arranged that the cyanide equipment t together 0 g e t h e r with the rest of the mill equipment Is such that the ores may be cyanided direct or may be first amal amalgamated abated and concentrated or be subject to any other method used in modern pra practice atice by an ingenious system of launders hoppers etc the entire plant is made extremely flexible in operation and in testing the ores may be sent over any piece of m machinery at will and the separate products collected with accuracy and dispatch wet concentration for wet concentration work the ore is screened on an anaconda type four callow screens or the fines may be classi fled fied on a richards hindered settling classifier and then sent to the jigs tables and banners van ners in the actual running of the plant the entire process is continuous thereby duplicating actual mill conditions in a larger equipment the magnetic separator the magnetic separator consists of one wetherill electro magnetic machine and one dings magnetic machine the wetherill machine is used for separating ores which are magnetic under a powerful magnet by this means garnet and zinc blend having almost the same specific gravities may be separated and there are many examples of minerals which can be treated by this means also a separation is affected between magnetite from other minerals and its gangue monazite from placer black sands and pyrite iron or copper from zinc blend also many others which are difficult if not impossible to separate by water concentration cent ration at times it is possible to make such separations direct with the lVe wetherill therill machine although in some cases a preliminary roasting is necessary or advisable to render some of the minerals more susceptible cep tible to magnetic treatment in such event the company resorts to its dings magnetic separator a low potential machine but very simple effective and cheap to operate the magnetic separation is largely used in the concentration of lead and zinc ores high in iron and covers an important field in ore dressing macquisten tubes the plant is equipped with a set of macquisten tubes the invention of mr A P S macquisten and which patent is owned by the american direct concentrating company of this city in their present state of perfection these tubes are meeting with sue suc cess in treating ores which have hitherto not been amenable to any other method of concentration they are especially adapted to the separation of zinc blend from barite sedi rite and other minerals having about the same specific gravity as blend many tests have been made with these tubes and they are available for use at all times before installing these tubes at the morning mill at mullan idaho a series of tests were run on the tubes here and the results at the mill showed a better recovery and a higher grade product being made than was obtained in the test size of mill tests A tenton ten ton lot of ore Ps is used for a regular mill test run although a preliminary test using to pounds is made before x la ap dings magnetic separator crusher plant consisting of rolls crusher and sample grinder I 1 am indebted to mr gayford for the information and courtesy extended to me during my inspection of the plant and I 1 am informed by him that visitors are always wel come E B HAYES macquisten tubes a regular test is attempted in the preliminary tests the characteristic features of the ahe ore are determined greatly facilitating the work in the regular run the company is also equipped upped to handle all classes of test work on a small scale its equipment including smaller machines especially built for making tests on lots from to pounds as well as on a tonnage basis the results from these small tests being equally as accurate and reliable as those from the larger I 1 tests for the preliminary testing two small two compartment hartz jigs one small wilfley table classifier settling tank agitation cyanide flasks flacks for cyanide testing and amalgamation plates are used the plant is also equipped with a complete laboratory |