Mine Sampling And Valuing; A Discussion Of The Methods Used In Sampling And Valuing Ore Deposits, With Especial Reference To The Work Of Valuation By

MINE SAMPLING AND VALUING A Discussion of the Methods Used in Sampling and Valuing Ore Deposits with Especial Reference to the Work of Valuation by the Independent Engineer - 1914 - CONTENTS - PART I. MINE SAMPLING. PRINCIPLE U S N DERLYINGM INE SAMPLIN A G ND VALUING D . efinition of ore. Sampling for valuation ...................................... PICK ANALYSIS. Objects. Work preliminary to sampling. Optical inspection ......................................................... CHAPTER IV. GENERALM ETHODS OF SAMPLING. P reparation of exposure. Quantity per foot sampled. Interval sampling. Fractional sampling. Sampling rises and winzes. Sampling cross-cuts. Measurement of width sampled-............................................................ CHAPTEV I . CHAPTER VII. CHAPTER VIII. HANDLIN OF G S AMPLES N . umbering the samples. Description of sample. Sacking the sample. Tying and sealing .......................... 64 CHAPTER IX. PREPARAT O I F O N SA MPLE FO S R ASSAY. Division of sample. Fineness of crushing. Preparation of the pulp. Final sample.. ................ 69 CONTENTS MINE VALUING. CHAPTERX I. ESTIMATI O O F N O RE. Calculation of averages. Check sampling. Erratic high assays. Assay plans. Calculation of tonnage. Inaccessible ore. Irregularly spaced drill holes ...................................... 83 CHAPTER XII. ORE IN SIGHT. Definitions. Ore Reserve plans. ....................... 103 CHAPTERX III. CALCULATION OF PROFITS. Treatment problems. Working costs. Base metal prices ....................................................... 111 CHAPTERX IV. CHAPTER X V. WRITING REPORTS ..................................................... 120 CHAPTERX VI. SALTIN . G .............................................................. 125 CHAPTER XVII. PROSPECT N S e . w discoveries. Re-opened old mines ................... 129 CHAPTERX VIII. A FEW S PECIA C L A SES. Miners as samplers. Checking surveys. Dress-ing mines for sale. Misrepresentation of facts.. .................... 132 CHAPTER XIX. CHAPTERX X. THE SAMPLING O F PLACER D EPOSITS. By Chester Wells Puringto z. PRELIMINAR G Y en . e ral classes of deposits. Characteristics of the pay layer. Origin of auriferous plains. Distribution of pay channels h . the plains. Preliminary remarks to sampling. Conditions affecting value of property. Instruments and equipment. Rocker and clean-up boxes. Hand pumps. Prospecting by shaft-sinking. Type of drill. Drilling with power drills. Calculation of value. Drilling with hand drills ............................................................. 140 INTRODUCTION. In the past a great deal has been written on the subject of mine sampling and valuation, but for the most part the literature is fragmentary, and I believe that scarcely anywhere is there any reference made to its elementary side. Somehow or other, engineers pick up a knowledge of this part of the business, although I do not think that the methods of mine sampling are taught in schools of mines, nor do the text-books on mining deal with it in detail. A few years ago T. A. Rickard, who at that time was editor of the Engineering and Mining Journall of New York, wrote a series of articles that were followed by contributions from various engineers. These articles and the ensuing discussion were eventually published in book form with the title of The Sampling and Estimation of Ore in a Mine. Aside from this, noattempt at a comprehensive work on the subject exists, and for that reason Mr...