Show economy in in mill construction construction io n BY RDWARD EDWARD HAAG M E companies engaging large capital in mining enterprises have long been recognized as pioneers in the introduction of varied and useful methods making for increased efficiency and economy in mining and milling operations the large and gratifying returns resulting from some improvement in ill the metallurgical process on a machine or some other detail of construction has 11 as encouraged continued eferts in that direction and large expenditures have been ventured for alterations in equipment etc to gain a saving in the cost of milling or attain a letter better percentage of extraction this is a splendid field for the intelligent mill man of practical hent bent to put his art to use for scarcely anywhere else is one so quickly and tangibly repaid for any little improvement applied to 10 machines or process if one can reduce the milling cost hut but five cents per ton of ore treated this would represent a saving of 5 per day for a plant handling tons which means per month and the device will pay for itself inside of one year even if it had 1 cost 1800 in fact the result fesui t attained would warrant an expenditure of considering 10 per cent as a good interest on the money invested many improvements have been inaugurated in this way and have become the public property of the industry giving the results of months and years of time and of large outlays of money to the engineer of today this of course is of particular value for f or the engineering problems of entirely new plants here again the large companies prove examples in skill and economy and the manner in which a new mill is engineered is worthy of careful consideration for any one facing similar task systematic P reparation preparation we find here at the outset a systematic and thorough preparatory worx work as the basis for any and every outlay or acquisition those who could most easily venture upon a financial risk will however refuse to spend anything upon a ai project that is not fully engineered and submitted in detail they will not listen to a mere guess as to building costs a probable daily output or an expected operating expense such data are wanted with a degree of accuracy that precludes a hazardous financial game and it is obviously as important to know the cost of milling as it is to know the average contents of precious metal in a ton of ore here then apart from the problems of the underground work a flow sheet is worked out for the proposed mill based upon the results of the assay office W hellman building los angeles investigation invest gation machinery suited to the particular requirements is selected the is carefully chosen and surveyed plans showing in detail the excavations a are e drawn up foundations machinery structure drive shafts down to the knee braces and bolts and no little time and effort is spent in tile the preparation of a minute specification of the whole plant that all this would w be done for the sake of exercise or for style no one would believe it rather shows what hardheaded mining men of experience consider real economy it is regrettable reg retable that many refuse to take that view and insist on being able to meet mee t problems as they come we gladly leave it to the man from missouri to draw his lessons after a failure it is easier and more convincing but we prefer ther the counsel of the successful to the careful observer it is evident that too many plants are born into the world with a handicap that can never be overcome by any amount of skill or economy simply because they have been denied the assistance of professional aid at the time of their throes 4 most of the failures in mining enterprises may be found in either one of two classes those failing because of lack of pay ore and those failing because of lack of capital the cases are very rare where a showing of ore justifying the erection of a mill has not held out long enough to pay the investors a good profit and other cases of the first class must be looked upon as schemes of unscrupulous men preying upon tile the unwary public for money doing a contemptible business entirely foreign to the mining industry lack of capital but speaking of the latter class we find that usually a fund has been raised to launch things yet it has failed to hold out to the coveted time when the wheels turn and bullion is the reason is plain insufficient capital it has deadlocked many a good prospect unforeseen expenses have come in delays of many kinds in the progress of construction the delivery of the material additional orders placed and waited for a larger payroll pay roll than anticipated possibly some unfortunate turn of weather an accident perhaps unimportant in itself yet fatal at this time or other such causes have combined to throttle the life out of the project considered calmly however we would differ as to the of the case and would rather call it insufficient engineering this is apt to occur under the condition of the smaller company or the individual owner who is bound to husband the funds and is seeking to economize wherever possible the common but deceptive mistake being entertained that a successful 0 mill can be built on the homemade 6 principle the engineer ignored and his services I 1 furnished by the boys 10 in this manner many of the problems involved are not faced their importance is 1 not recognized or is argued away and matly many are not even approached because of lack of foresight and some may be for fear of the cost the deceptive appeal for economy hampers liam pers thorough work at ai tills this critical stage the investors or owners seeking advice from the miner superintendent some I 1 friend or other qualified persons and will I 1 count themselves lucky thus to have saved themselves the expense of the engineers service they will write to the machinery house for prices and more information and are gladly served with quotations and recommendations not being acquainted however with the peculiarities of their proposition and hardly willing to go to the trouble of looking into it beyond what is being told him the dealer can not find any reason why his proposal should not just fill the bill exactly failing however thus to take proper account of all conditions the management often happens to find results quite disappointing and sometimes disastrous and then wonders who should be blamed for it if it seem unfair to belittle the cherished plans followed by so many it may yet prove profitable for such as may in similar circumstances feel inclined in that same direction for it ought to be put down as an axiom that all economy is thrown to the winds as soon as any one attempts to build a plant without having a clear and complete conception of it on paper one might as soon start the laying out cut of a road without a map the most important stage th the e most important stage in the making of a mine is reached when tile the mill is decided upon the mill is the pulse of the mine if it stops the mine is dead never will there be more need of careful delabra tion and thorough study than when the mill is being laid out A mine is worth no more than the mill can produce the output of the mill then is paramount and to obtain the highest efficiency both financially and mechanically is the ambition of the construction engineer by financial efficiency we mean the relation of the capital invested to the capacity the mill is able to attain while the mechanical Ine chani efficiency is measured by the amount of power expended per ton of ore treated the former depends next to the arrange arr arrangement alge of the flow sheet upon the correct selection of the machinery the latter upon its disposition in the plant various other factors of course bear upon the efficiency in the of the mill which are more or less aa ind hands of the engineer to manipulate for fo the e to weigh and balance their value most economic result is the problem before t the mill builder A mill economically ar 1 r ranged uses a minimum of power has centralized t drive as much as possible uses a minimum of hand labor and is compact for convenient oversight and superintendence unnecessary handling of the material i is s avoided machines requiring attention are given plenty of light and access room is left for the easy and quick exchange of wearing parts and proper safeguards for the employees are provided other items f pecolar to the individual machine are considered and even the possibility of unfortunate un manipulation tion might call for recognition breakdowns are not always serious but might at some time or other put the whole works out of comm isison for days especially when repair parts carts are wanted from the east wherever that may be yet the possibility of a breakdown is not en beyond conjecture and with some forethought the weak spot may be detected and reinforced or emergency bypasses by passes provided all of which seems easy enough when a good and completed set of drawings is on hand it cannot be the object of this article necessarily general in character and scope to bring out all the many items peculiar to specific propositions but the above will suffice to show the value of careful study preparatory to mill construction it is needless to say that only complete plans drawn to scale and specifications can reveal such points and form a basis for criticism value of drawings it is the good service of drawings to per amit mit exhibition to the eye of ideas enter stained bained in our minds what the observations and experiences of years have impressed upon us and the principles formed to work vork upon can be pictured in clear and definite outline on paper and hereby only our ideas usually vague and shapeless get really e clarified lari fied and accurate As we lay down to the vision of the eye conclusions formed upon invisible assumptions matters begin to condense down into concrete form and 9 definite shape and either assert or deny our expectations ithe drawing is a check and test of the ind and will therefore prove of great value find hen capital must be risked upon the strength of ideas coming under the eye of anany any critics by means of drawings errors p f conclusion false impressions and other ni stakes in the case of a milling plant for ns tance will be detected and can be remedied led without much trouble there a mill f built at random this cannot be done nd d even serious misconceptions of the builds cannot be found out until they have en executed and which will entail great pense and loss in having them correct corrected that at be possible at all necessary in getting bids besides affording this ills valuable opportune ity for checking criticism and the drawings provide the only means for obtaining reliable and binding bids on the machinery and material for the plant every item can be singled out and specified accurately cura tely and the different classes of goods may be drawn out and submitted to leaders in their respective lines this should always be done at the engineers office so as to preclude the possibility of a manufacturer fac overlooking some parts of the plan in his bid and the contractor then being obliged to send for such later when the construction st has proceeded to the point where the mission om has stopped the progress complementary orders are always costly on account ac count of the delay in the delivery the extra freight the extra price asked for them and for many other reasons A bill of material picked off the drawings will avoid all this and it is welcomed by the bidder and is a protection to the buyer it will bring all the goods on the ground in time and in proper succession cuc cession avoiding delays on one hand and crowding on the other estimate of cost in this connection it must further be said that not only must the engineer be given time to establish complete drawings down to such details as may need special cial elucidation but he should also prepare an esti mate of the cost of construction this may entail quite a little expense as it will require personal examination of the locality and study of the labor situation railroad facilities the cost of freighting cost on the ground of excavation of cement gravel etc etc it may not occur to many that the cost of machinery for a mill is often only half of the expenditure required to get the wheels to turn in the case of smaller plants especially it would therefore save much disappointment to make ample provision for this item by ascertaining its size before hand to some it may seem sufficient to arrive at the amount of this item by simply averaging three guesses but aey they are apt to find another guess coming it might be easy to enlarge upon this prolific theme and an amazing chain of examples produced to substantiate our contention yet little benefit could be expected and we would be afraid of provoking the patient reader because of having spent do much time in the defense of what seems a self evident matter that even this Is not entirely out of place however is shown by so many enterprises that have run aground for such reasons and have thus helped to feed the unjust suspicion that so long has been abroad against the cleanest and most profitable industry of the country |