IV. THE CHEMIST IN THE LEAD-SILVER SMELTER FRANKLIN G. HILLS
For about thirty-fiYeyears, the contributor of this article, Mr. Franklin G . Hills, has been actively engaged as a chemist in the smelting and refining of ores. During the past eleven of these years he has been chemist at the Experimentul Plant of the Colorado School of Mines. He was graduated with honors from the New York College of Pharmacy. In addition he spent some time in Columbia University as a s#ecial student. He is the author of several articles on chemical analysis and also a book, "Technical Analysis of Ores and Metal Products," which is being published by the Chemical Publishing Com#any.
In the lead-silver smelter the chemist supplies the figures by which all operations are controlled. He also supplies the figures on which purchases and sales are made. The blast furnace slag mnst be analyzed probably twice a day. This requires speedy and accurate work. Speed and accuracy are not, as is sometimes thought, incompatible. Slow work does not of necessity imply accuracy, nor does speed imply rough or inaccurate work. Skill is required in the working laboratory, and the art of analytical chemistry is as important as the science. Both are necessary. The chemist will receive, perhaps, as many as fifty samples from the roasters daily to be analyzed for sulfur, and samples of ores on which must be determined the elements necessary for settlement. The bullion and matte which are sold must be analyzed for the necessary elements, and full analyses are often required. Special problems are often presented and require both knowledge and skill for their solution. As an example, the writer was told by a plant manager late one afternoon that beginning the following day they were going to segregate bismuth-bearing ores on a basis of '/M per cent. bismuth, and analysis would be required on every car of ore entering the plant in time to avoid demurrage. A method was developed which proved an accurate one by which results were reported in ample time. As many as twenty samples were received in the afternoon on which bismuth was reported the following morning. This method has been successfully used in exacting work. Industrial pressure is responsible for the development of many industrial methods which have been found to be, or have been developed into, very accurate methods. This industrial pressure is illustrated by an incident which occurred in a steel plant owned by Mr. Carnegie, who was the first man to employ a chemist in the steel industry. In the determination of phosphorus a gravimetric method was used and the result was not obtained until the day after the sample was received. At a
certain plant improvements were being planned which would require results more promptly. The superintendent said to the chemist that he had to have phosphorus on those steels in two hours. "Ican't do it," said the chemist. "There is no method known by which phosphorus can be done in any such t i e . " "I know that," said the superintendent, "but it is up to you to find a way. I must have those results in two hours." As a result of such pressure, a steel chemist will now ordinarily have a phosphorus determination in one hour and on some steels in less than thirty minutes and it will be accurate. Variations in duplicate samples will not be more than 0.002 to 0.003 per cent. These samples illustrate the pressure brought on the chemist in industrial work. It is necessary to adapt the job to the requirements. Methods are sometimes used which give only approximate results, but approximate results satisfy the requirements. I t is essential for one to realize the importance of time. For instance, fifty sulfur results done accurately would require all of one person's time for more than a day, but done accurately the results would be of no value, as they would be received too late to be of use to the plant. The metallurgist, in this case, is interested in approximate results withm 0.5 per cent. These results can be given in a few hours. The writer has done seventy sulfurs, two complete slags, and a half dozen mattes in the forenoon, giving results that were satisfactory as a careful check has shown. This is an excessive amount of work, but it illustrates what can be done. Analyses for purchase and sale of material are usually more exacting in their requirements. But these samples are being received daiiy, and it is necessary to do the work cnrrently in order to avoid congestion. The shipper has his own chemist and the results from his laboratory and the smelter must practically agree in order to obtain a settlement. It is evident that the results must be correct or there will be extra work, for in case of disagreement the work mnst be repeated, and a number of repeats each day will increase the work materially. The results cannot be in any case better than the sample, and prompt approximate results which give the desired information are of more value than extremely accurate results which cause a waste of time with no corresponding advantage. The importance of accuracy must not be m i n i i e d , but good technic is also of great importance. The function of the school is to transmit knowledge and to develop a good technic-but it does not have the facilities for developing the ability to handle a large volume of work. This ability can be acquired only in the industrial laboratory.
Ores are carefully sampled in the smelter for assay and settlement, but grab samples for various purposes are often submitted to the chemist. Results on grab samples are usually required and submitted with promptness. An extremely careful analysis on such samples is a waste of time for the chemist, and a source of annoyance to the metallurgist who is forced to wait for the results of the chemical analysis. The smelter chemist will have a busy, exacting job, but it will be an interesting one. The doing of routine analysis is deadly unless he will follow up the application of his work to the plant operations. If he does this he will doubtless in time become the metallurgist himself, which involves routine work of another sort. [Mr. Hills points out that the possession of degrees is not sufficient to assure success in the chemical profession.] Of course, the man should know his chemistry, both theoretical and practical. The latter he may have to get on the job, but it is important. This does not mean necessarily the possession of advanced degrees. These are often a hindrance because the man who has them thinks they are synonymous with knowledge. Nothing could be farther from the truth. The most hopeless man with whom I ever worked had three degrees. A fourth would have ruined him. He had neither knowledge nor skill, but, because he had acquired
his degrees, he felt that information from a more humble source was not worth his consideration. Degrees are rapidly losing their significance, especially to men who must deliver the goods. This does not undervalue advanced training; it means that much of the so-called training is inadequate. [Mr. Hills is not the first contributor to mention the matter of honesty. However, because of his strong convictions on the subject, his comments are given below.] Honesty is perhaps the most desirable qualification of any chemist. A dishonest chemist is almost unthinkable. In his work he should always report his result, right or wrong. Of course, for the most part his work must be right, but no man is infallible, and a chemical determination is a delicate operation. However, the chemist should never guess at a result. If there is doubt as to its accuracy he must repeat. Get the truth before reporting, or tell the interested party of the question, if difficultiesare encountered. One of my assistants told me that his professor would have nothing to do with a man whom he once caught in a dishonest act. I believe that idea to be fundamentally correct. Incidentally, to my personal knowledge, that particular school has produced some real chemists.
