"FACTS ��u FIGURES�' CONr.ERNING COAL W ASH'ING BY THE LUHRIG PROCESS: WITH NOTES ON THE MANUFACTURE OF COAL BRIQUETTES. Press of Mortimer L. Williams, No. 28 Elm Street, New York CONTENTS. -'lads anh ligUfU" concerning «oal �asVing. PAGE. INTRODUCTION, 9 THE LUHRIG COAL WASHING PROCESS, It LIST OF COAL WASHING PLANTS ERECTED IN EUROPE BY C. LUHRIG PREVIOUSLY TO DECEMBER 3 I ST, 1889, 18 LIST OF ORE DRESSING PLANTS ERECTED BY C. LUHRIG PREVIOUSLY TO DECEMBER 3 t ST, 1889, DESCRIPTION OF A NEW COAL WASHING PLANT AT FERDINAND GRUBE, KATTOWITZ, IN UPPER SILESIA, SOME 01' THE ADVANTAGES OF THE LUHRIG PROCESS, 39 4 PAGE. REPORT ON L'lJHRIG'S SYSTEM OF COAL WASHING, BY PROFESSOR KREISCHER (ROYAL SCHOOL OF MINES, FREIBERG), 47 ESTIMATES OF PROFITS, 54 (A) Saving in the Pi�, 54 (B) Saving in using up Mixed Coal, . 54 (c) Saving in Coking, 55 (D) Increase of Lump Coal, 55 (E) Recovery. of Bye-Products (Pyrites), 56 Total Savings, 56 ESTIMATE OF PROFITS AT HEINITZ COLLIERY, SILESIA, 57 ApPENDIX:- I.-TESTS MADE AT BRUCKENBERG PIT No. II., NEAR ZWICKAU, 60 n.-TABLE OF RESULTS OF DAILY ANAL­ YSES FOR ASH IN COKE MADE AT BOCHUM, 66 COAL WASHING FOR COKE MAKING, . 68 5 �tnttS .an iqe �bnnfadutt .at 'Dal �riqutfttS: PAGE. INTRODUCTION, 77 NOTES ON COAL BRIQUETTES, 79 ESTIMA TE OF PLANT, • DESCRIPTION OF MESSRS. MOWLL & MESSENGER'S MACHINE, 83 TABLE OF VARIOUS TYPES OF BRIQUETTE PRESSES, 85 TABLE OF COMPARATIVE PRICES FOR 1885,. 86 DESCRIPTION OF PRESS FOR THE MANUFACTURE OF SMALL NUT BRIQUETTES, COST OF PRODUCTION, INTRODUCTION. �t)f"t)f"t)f"t� . 11I�\,§"IIIIIIIIIIIIII"iI�I�"HE arm of this is to direct the +-: ...T..... ::::.+ pamphlet (I� � �I; public attention to the important 'subject ��III� !II� of coal washing, the numerous advan­ �i! t li� tages connected with the use of clean. 1111111111111111111111111111111111111111 ..... ..... ..... )(+ ;(+ ;(+ )I'+� coal, and a cheap and economical pro- cess of cleaning it. THE problem of coal washing is an extremely com- plicated one, and the few words on the subject contained herein are merely intended to awaken the interest of the coal owner, the coke manufacturer, and the iron and steel master. IT is to be hoped that the Report by Professor Kreischer, an authority on all minmg matters, and especially on coal washing and ore dressing, will be of interest to mining men. Although this Report was written in 1882 it will be found to contain some quite interesting matter. Since the issue. of this Report the Llihrig System has undergone a great many improvements. THE description of the plant at Kattowitz, which contains many late improvements, sives a fair idea of the process. MOST of the figures and tables are taken from practical tests made by Professors Kreischer and Nonne. THE list of plants erected, and the map of the spread of Plants built on the Llihrig process has been revised by Mr. Llihrig himself, and is correct up to the 31st December, 1889.. 9 The Process has been extensively adopted at the largest collieries in the following countries:- ENGLAND SCOTLAND FRANCE BELGIUl\I AUSTRIA HUNGARY RUSSIAN POLAND RHEINISH PRUSSIA WESTPHALIA SAXONY UPPER SILESIA LOWER SILESIA BOHEMIA HANOVER Plant is now being erected in­ GREECE ASIA MINOR ALGIERS 144 complete plants on LUHRIG'S System have been erected by him and working previous to December 31st, r889. (See accompanying Map.) TIlE LUHRIG COAL WASHING PROCESS. the last few years coal has . mining - made it really necessary for most collieries - J coal ��! I�IIURING� to be supplied with good washing plant, and the work of the coal washing engineer has been made more and more difficult and complicated in proportion. WHILST formerly colliery managers built coal . washing plants according to their own notions and ideas, the erection of such plants is now generally put into the hands of a coal washing specialist. A G REAl' deal of machinery for use in the mechanical separation of coal is made and sold, but the arrangement of such machinery, and the general and economical disposition of it, is generally looked upon as a secondary matter by the manufacturers. In short, there is usually a 1MIlt of that systematic arrallge- men: 'which 'would b,-illg about a process sltit(lble fiir the economicai cleansing of the coal. THE perfecting of such a process has been the ex- clusive work of Mr. C. Llihrig during the last 25 years, and he has been eminently successful in the United Kingdom and on the continent of Europe, as both the map and list of plants erected will show. T HIS process is the result of a long and varied experience with some of the most dirty coal on the continent of Europe, and is on the gradual reduction system, that is, if the washed coal is to' be �oked it is not all crushed up in a dirty state, but gradually broken up, the shale being automatically separated from the coal by degrees. T HE process essentially consists of:- Dry separation of the run of the mine, that is, the mechanical separation of the slack or dross from the lump coal. Coal which passes between the bars of a screen about three inches apart or through a reciprocating screen of three inch to four inch mesh, is generally treated in the washer. In many cases the lump passes on to picking and loading bands, where the shale and interstratified pieces are picked out by hand. 13 All larger pieces of coal, when interstratified with shale or mixed with pyrites, are broken and again passed over the screens for reseparation. Sl'jaratioll of the slack or dross' by screening, the dross is raised into revolving screens for the purpose of sizing the coal for the production of nut, pea and fine coal. Tprashillp,- the different sizes of nut coal coming from the revolving screens, each on separate machines, so that each machine only works up coal 'of uniform size. Cmshillg the mixed or finely interstratified coal (separated by washing from the pure coal and clean refuse), for re washing on separate machines. Gradillg the fine coal from the �Is downward from the screens, and that carried by the water from the nut coal washers, into different classes ac­ cording to specific weights. TVashiizg each different grade or class of fine coal on separate washers especially constructed for the treatment of fine coal, their work being per­ fected by the help of feldspar; this was first employed by Mr. Liihrig in coal washing ma­ chinery, and has given very satisfactory results. The 1,{,(0'Z'e1), of sludge, or "schlamm," which is so difficult to retain and which often contains exactly what is' essential to coking in the case of a coking coal. This is done by means of automatic and continuous sludge recovering machinery. Filterillg tlte 'water used in washing, and cleaning it to such an extent as to enable its re-use again and again. TIle- automatic transport of the vhrious products, nut, pea, pearl and fine coal, al,so of refuse, both fine and coarse. Ecconery of bye-prodllcts, as, for instance, pyrites or brasses, which in many of Llihrig's plants pays the cost of labor. Arrangements are also made for automatically storing a considerable quantity of coal, the hoppers being so arranged that a large quantity of coal can be loaded in a short time. The dry separating portion of the plant is con­ structed so as to make as little "smalls" as possible, the screening and loading arrangements being economical, efficient and automatic. The washing arrangements are such that as much dean nut coal can be extracted as possible, and that tIlref prodllcts can be made by each machine, viz., clean nuts, seconds or nuts inter­ . (finely stratified with shale), which are raised, crushed and rewashed, and c1ean refuse. I N all of Ltihrig's plants there is a marked desire to> avoid crushing all the coal, that is, the dirty and clean coal together; this is so often done at collieries using single apparatuses. Such a system always leads­ to the productionof a great deal of unnecessary fine or dust coal, and consequently to loss of coal in the­ washed-out refuse; unless the coal is very finely inter­ stratified it is always washed previous to crushing for coking. IT should be borne in mind that it is not claimed that �his is one machine suitable for every class of coal, but that it is a process 'which call be so arranged as to meet the requirements and local conditions of eaclt coi/iery. The nature of the coal to be treated is always taken into account, also the purpose for which it is. intended to be used. IT follows that every plant is different and that copying and imitation of previously carried out designs and plans is generally faulty and disappointing. MOREOVER, success does not alone depend upon machines and apparatus, which can be made at almost any engine works, but upon the process and the system upon which the whole plant has been built and is operated. AT the same time, every part must be easily accessible, open to supervision and under complete control. IT is not possible to enter into a full discussion on this process of coal washing, but only to indicate the general principles upon which it is based; suffice it therefore to say that the process is automatic, continuous, that the cost of working is almost only nominal, and that it has been adopted by the largest and most important collieries in Europe, as will be seen by the appended map and list.