Carboniferous Coal Measures Research Articles

本溪湖に於ける低燐銑(純銑鐵)の製造に就て

The Miao-erh-kou iron mine is situated at about 20 miles north east of Pen-hsi-hu on the Anfeng line (between Antung and Mukden) of the South Manchuria Railway. The ore deposit is of magnetite in bedded intercalated in schistose plane of granitic gneiss and mica-schist of Pre-Cambrian age. The present annual output of the rich ore (65% Fe) reaches to about 240, 000tons.The ore concentrating plant is in the vicinity of the Nanfen station, about 5 miles apart from the mine, and there magnetic concentration of the rich ore or dephosphorization is operated by the Gröndall process. The annual capacity of the plant can be reached to 110, 000tons after its recent extension.The concentrated ore is transported to Pen-hsi-hu by railway and there briquetted by the, press machine and desulphurized and oxidized into hematite composition passing through the Sutcliffes tunnel kiln which is heated by coke oven or producer gases. There are two kilns, each capacity being about 40, 000tons per year. The briquettes are porous, reducible, and very pure as shown in following analysis:Fe 69% SiO2 1% P 0·007% S 0·009% Porosity 25%The coal field at Pen-hsi-hu consists of carboniferous coal measures with 8 seams of semi-anthracite. It has strong caking power, and is suitable to use for making coke. Above all, coal in the Poza seam which is the uppermost one is very low in phosphorus and sulphur, so we can make low phosphorus coke from it through the Kuroda's byproduct coke ovens after careful washing. The standard analysis of low phosphorus coke is as follows:-F.C. 83% Ash. 14% P 0·01% S 0·45%Besides these two chief raw materials, we purchase some manganese ores which are low in phosphorus. Limestone as flux, forms the base of the Pen-hsi-hu coal mine, and quarzite-pebbles are also found at the riverside near the works. In every one charge, a small quantity of quarzite is mixed for two purposes, one is for supplementing necessary Si in pig iron produced from briquettes which contain insufficient SiO2, and the other is for the safety of desulphurization in pig iron keeping the moderate slag quantity with limestone in quite basic compositions.At the Pen-hsi-hu Iron Works, there are two blast furnaces, with daily capacity of 200tons each, and various foundry, basic, and low phosphorus pigs ammounting to 150, 000tons per year are produced, of which about 50, 000tons being low phosphorus this year (1934). To make low phosphorus, the above mentioned raw materials are used in proper mixture in charge, and we succeeded in it by carefully controlling the furnace running with a small quantity (30-35% per ton pig) of moderate basic slag, and using quite high temperature blast. We are able to produce very pure iron which is low in P, S, Cu, and Si as same as Swedish charcoal pig, and also low in P and S, but high in Si and Mn such as hematite pig according to demands. The analysis of the Ist class which is main product, is as follow:-P 0·025% below S 0·015% below Cu 0·015% below Mn 0·50% above Si 1·0% aboveAll the low phosphorus products are exported to Japan and mainly used in acid open heartbs.The demand in Japan has increased rapidly since two or three years ago, especially in this year its demand has reached to about 50, 000tons. The importation of low phosphorus pigs to Japan hither to made from Sweden and England is almost excluded at present.In near future, we shall be able to produce 75, 000tons a year by further enlarging the briquetting plant.

The Flora of Leicestershire, including the Cryptogams

THE county of Leicestershire covers an area of 800 square miles of the centre of England, at the summit of drainage between three of the great streams, the Trent, the Severn, and the Midland Ouse. Almost the whole of the county is at least 100 feet above sea-level. A large portion of the surface is between 300 and 500 feet, and Charnwood Forest rises at its highest point to 900 feet, so that Leicestershire is very different from such low-lying level Midland counties as Cambridgeshire, Bedfordshire, and Huntingdonshire. Half the area of the county is in grass, about one-quarter is under arable cultivation, and there are 20 square miles of woodlands. In Charnwood Forest there are slate and granite, and the sedimentary rocks are represented in the county from the middle of the Palaeozoic to the middle of the Mesozoic series—Carboniferous Limestone, Coal-measures (Permian missed out), Trias, Lias, and Lower Oolite—so that there is every variety of soil. The Flora of Leicestershire, including the Cryptogams. With Maps of the County. Issued by the Leicester Literary and Philosophical Society. 372 Pages and 2 Maps. (London and Edinburgh: Williams and Norgate, 1886.)

Note on the Relations of the Supposed Carboniferous Plants of Bear Island with the Palæozoic Flora of North America

I have only recently received the May number of the ‘Geological Journal’, containing the interesting paper of Dr. Heer on the plants above mentioned, and beg to request permission to address to the Society a few remarks on their supposed equivalency with the American Devonian Flora. The plants catalogued by Dr. Heer, and characterizing what he calls the “Ursa Stage,” are in part representatives of those of the American flora which I have described as the “Lower Carboniferous Coal-measures” (Subcarboniferous of Dana), and whose characteristic species, as developed in Nova Scotia, I noticed in the Journal of the Geological Society in 1858 (vol. xv.). Dr. Heer's list, however, includes some Upper Devonian forms; and I would suggest that either the plants of two distinct beds, one Lower Carboniferous and the other Upper Devonian, have been near to or in contact with each other and have been intermixed, or else that in this high northern latitude, in which (for reasons stated in my Report on the Devonian Flora) I believe the Devonian plants to have originated, there was an actual intermixture of the two floras. In America, at the base of the Carboniferous of Ohio, a transition of this kind seems to occur; but elsewhere in North-Eastern America the Lower Carboniferous beds are usually unmixed with the Devonian. Dr. Heer, however, proceeds to identify these plants with those of the American Chemung, and even with those of the Middle Devonian of New Brunswick, as described by me—a conclusion from which I