May 3, 1918. _______________________________________________________________________________________________________________________________________________________________ ___________________________________________________________________________________________________________________________________________ THE COLLIERY GUARDIAN. 905 SOUTH WALES MINING TIMBER TRADE. It is believed that the Government intend to consider the further restriction of pitwood imports, in order to conserve shipping tonnage. South Wales receives the largest amount of foreign mining timber; but the trade is conducted in small steamers and sailing vessels regularly- plying between South Wales ports and the near French ports in coal. If pitwood is not carried as a homeward cargo, these vessels are obliged to come home light or in ballast. 1 bus, further restrictions, so far from conserving shipping tonnage, will hamper its efficiency. There are other reasons why the present regulations should be made more elastic. Thousands of tons of wood await shipment at the near French ports, and if supplies were taken in larger quantities by the smaller vessels, quotations on the Cardiff market would fall below the level of the present fixed price, to the advantage of collieries and also to the State now that the collieries are so fully controlled. There is also the consideration, moreover, in the near future home-grown resources will tend to become lessened Collieries should have a much larger margin of pit wood stocks, in order to be on the safe side. Imports of the Admiralty Pit wood Committee. The efforts of the Admiralty Pitwood Committee in sup- plying the collieries on the Admiralty list with pitwood have been successful. Their agents abroad have made regular and sustained deliveries possible, and collieries have been quickly supplied. It is highly provable that this committee will continue its operations after the war. The committee receive five-eighths of the total quantity of foreign wood allowed to be imported, and assemble and deliver same to the Admiralty collieries at the minimum of cost. Having their agents abroad they are enabled to send those sizes which are the most suitable for the requirements of the collieries on the Admiralty list. The imports for the week ending April 26 amounted to 10,752 loads, of which 9,660 loads were received by the Admiralty Pitwood Committee. The details are as follow:— Cardiff (including Barry and Penarth) : — Date. Consignee. Loads. April 22 Morgan and Cadogan....... 420 „ 22 Lysberg Limited........... 1,920 „ 23 Lysberg Limited........... 1,200 „ 23 Lysberg Limited........... 600 „ 23 Lysberg Limited........... 300 „ 24 Morgan and Cadogan....... 672 „ 24 Lysberg Limited........... 2,160 „ 24 Lysberg Limited........... 2,880 „ 25 Lysberg Limited .......... 600 Total..... 10,752 Newport:—No imports received. Home Grown Supplies. Over 2,000 tons of Irish pitwood were received at South Wales ports last week, principally by merchants. The authorities import small supplies for the Admiralty collieries, which fact is considerably disliked by merchants engaged in the trade. As regards the supplies in adjacent counties deliveries have been fairly good, but there are many thousands of tons of wood lying about awaiting haulage. The scarcity of hauliers is intense, and cutting is pro- ceeding at a much faster rate than delivery. It is estimated that if the authorities do not remedy the matter, delivery of cut woods now lying in the forests will not be made until next winter, with the consequence that the wood will suffer considerable deterioration. South Wales and Foreign Supplies. South Wales receives the bulk of the foreign supplies imported into this country. During March last the total quantity of pitwood imported amounted to 68,499 loads, or 57,084 tons. South Wales received 62,170 loads, or 51,800 tons. The Midland and Northern colliery districts, therefore, are relying almost wholly upon home-grown timber. Experiments are proceeding at Cardiff and Man- chester with regard to concrete substitutes for pit props, but so far little advance has been made in their use. Nevertheless, the rapid denudation of our woods will bring substitutes to the- forefront. Last month the average value of the pitwood imported from abroad into South Wales amounted to 61s. lOd. per ton. The pitwood is sold at the maximum level of 65s. per ton, which leaves a gross profit of 3s. 2d. a ton to the importer. But loss by barking, etc., considerably reduces this average profit. _____________________ THE BY-PRODUCTS TRADE. Tar Products.—Pitch just now is a question of price, as tar is a question of quantity. Provincial quotations of pitch have risen to 28s. to 30s. on the east coast, 26s. in Liverpool, and 26s. to 28s. f.a.s. west coast. Meanwhile, the London quotation is firm at 50s. to 55s., despite the handicap of uncertain outlook regarding official action, plus the brake on exports. The London market encourages provincial holders to look for 30s. per ton, and the general tone is maintained accordingly on the basis of 26s. to 30s. A wider range is evident in the United States, for there the quotation for the various grades of pitch is 8 dols. to 20 dols. per ton. Crude tar has hardly changed since last week, and supplies are still a doubtful factor. Recent contracts include dehydrated tar at 4d. per gallon, to be supplied to Totnes Town Council by the Plymouth Gas Works. Benzol remains a good market commodity at last week’s quotation. In the United States benzol is quoted at 30 c to 35 c. a gallon, solvent naphtha 17 c. to 22 c., and crude solvent naphtha 13 c. to 16 c. In both countries the demand for these by-products is a sound one. Solvent naphtha has improved in price in London and the provinces, but some of these changes are influenced by expectations as well as by current facts. Not much is doing in refined naphthalene, and aniline oil is slightly on the down grade. Current quotations are as follow:— Crude tar : London, 32s. 6d. to 35s.; Midlands, 27s. to 29s ; North, 28s. to 30s. per ton ex gas works. Pitch: London, 50s. to 55s.; east coast, 28s. to 30s. f.o.b.; Liverpool, 26s.; west coast, 26s. to 28s. f.a.s. Benzol: London, 90 per cent. Is. 0|d. naked ; North, 10|d. to ll|d., 50 per cent., Is. 4d. to Is. 5d., naked. Solvent naphtha : Naked, London, 90-190 per cent., 4s.; North, 3s. 9d. ; 90-16Q per cent, naked, London, 4s. 3d. to 4s. 6d.; North, 4s. Crude naphtha: Naked, 30 per cent., 8|d. to 8^d ; North, 63d. to 6|d. Refined naphthalene, .£30 to .£32 10s.; salts, 80s. to 90s. Toluol: Naked, London, 2s. 4d.; North, 2s. 3d. Carbolic acid : Crude, 60 per cent., east coast and west coast 3s. 6d. (3s. 4d. naked) ; crystals, 39-40, Is. 3d. Cresylic : Casks, 95 per cent, 3s.; 97-99 per cent., 3s. 3d. to 3s. 6d. ex works London and f.o.b. other ports. Anthracene : 40-45 A 4|d., B l|d. to 2d. Aniline oil, Is. 2d., casks free; salts, Is. 2d., drums free. Sulphate of Ammonia.—Under a new Order of the Minister of Munitions trading in this fertiliser is regulated, maximum prices fixed, and cost of distribution equalised throughout the United Kingdom as regards sales for delivery after end of May. The average price to be paid by the consumer next season is as follows :—Sulphate con- taining 24i per cent, by weight of ammo’ ia <£15 5s. from June 1 to August 31; <£15 15s. from September 1 to November 30; ^£16 5s. from December 1,1918, to February 28, 1919 ; and .£16 15s. from March 1 to May 31, 1919. The decision of the Sulphate of Ammonia Association regarding terms is reported in another column. _________________________________________________ THE LONDON COAL TRADE. Thursday, May 2. The market has shown a strong active demand during the week. Merchants are compelled to pick up a large quantity of stock coal to keep pace with the orders on hand, and it is feared that unless supplies come forward in better tonnages than recently, a great shortage will be experienced in the London area. The requisition of so much railborne coal for the various Metropolitan gas companies has had a telling effect upon the available quantities for London. Merchants have found it impossible to replenish the diminished stocks on the ground whilst the present shortage is in force, and everyone has had notice that a curtailment of original quantities must be recognised and carried into effect to replace the diminution of the seaborne gas coal. The cold weather has largely influenced the consumption of house coal in the London area, and at the same time the provincial demand has enormously increased. Very few collieries have been able to accept any fresh orders for the London depots, and notices have been sent out in every direction pointing to a further reduction in the monthly contract quantities, all of which are behindhand. The time is rapidly approaching when warmer weather will reduce the actual consumption both of house coal and gas, so that it is hoped that even the limited output will enable supplies to be put into stock again. Recent reports show that the Ministry of Munitions is arranging to break through the old regulations about bringing Durham coals forward into London, and as many of these collieries are working short time on account of the want of vessels, this may open up a means of combating the present shortage at the gas works. The great point is the difficulty of the railway companies in- providing the necessary trucks for this purpose and for the long distance. Last week the number of vessels entering the Thames was seriously down, but on Monday an unusual number of 47 boats were returned as arriving, all loaded with contract coal. Many of these may have been held up through stress of weather, but they all tend to fill up a very critical gap. Two arrived for Wednesday’s market. No special issue is likely to be made of the “lowest summer prices” this year, but householders have again been urged to stock coal as much as possible during the summer months, owing to the transport difficulties and shortage in the output during the winter. A special point is also made of using lower- grade coals in the ordinary domestic grate to allow of the richer coal, with its valuable by-products, being more freely used for gas making. The new order restricting the supply of gas to consumers using it from the slot meters is to be made applicable to all. The gas companies are prepared to supply the information to any consumer who is in doubt as to his quarterly consumption in 1916 or 1917, but the total consumption must be one-sixth less than usual. Where coal is now being used in lieu of gas cooking, some consideration is to be given to consumers of this kind. The Westminster City Council applied to the London County Council for permission to purchase the usual supplies of coal and coke for their various establish- ments for the ensuing year, and the local coal overseer has been instructed to place the orders with the usual con- tractors, due regard having been paid to the stocks in hand. _________________________________________________ THE IRISH COAL TRADE. Thursday, May 2. Dublin. The demand for coal continues, notwithstanding the advanced season. Supplies are inadequate, as it is impos- sible to get cargoes over under existing conditions. At the end of last week some of the merchants’ stocks were com- pletely run out. There is no change in late prices. Best Orrell, 51s. per ton; best Wigan, 49s.; standard coal, 46s. 6d. per ton, delivered; coke, 49s. per ton. Irish coals at Castlecomer pits (County Kilkenny) :—Best small coal, 30s, per ton; best large coal, 28s. 4d.; bottom coal, 25s.; breakage, 16s. 8d.; culm, 13s. 4d. per ton. The total quan- tity of coal discharged upon the quays during the past week was slightly bver 24,000 tons, compared with 25,000 tons the week previously. Belfast. House coal is now in less request, owing to warmer weather, so that the shortage of the better qualities will not be so severely felt as during late weeks. Prices remain unchanged, as arranged by the Coal Committee of the Cor- poration, viz.:—Best English coal, 51s. per ton; English nuts, 50s.; English kitchen coal, 50s.; best English slack, 47s.; Scotch house coal, 45s.; standard coal, 44s. per ton net. The return of imports through the harbour of Belfast for the quarter ended March 31 shows that the imports of coal were 365,356 tons, as compared with 330,630 tons in the corresponding quarter of 1917. ___________________________ THE TIN-PLATE TRADE. Liverpool. t The extraordinary state of block tin has unsettled the tin-plate market, and many of the makers decline to quote at all for the present. The official maximum is generally asked by works which are open to book. Only favourable specifications which may be wanted are accepted at slight concessions. Wasters are in good demand, especially 28 * 20, which are very scarce, and top figures have to be paid. The “ ration ” permits now being issued to the home trade are helping works nicely to keep their stocks down. Terne-plates continue in very good demand. ______________________________ The Board of Trade has authorised an increase of 7s. 6d. per ton on goods and minerals carried between Great Britain and Ireland. THE IMPORTANCE OF COKE HARDNESS.* By G. D. Cochrane. The practical success of the working of a blast- furnace is chiefly dependent on the mechanical condition of the coke used, provided that the mechanical portion of the plant is in good average working condition. The percentage of ash in the coke and the analysis of the ash are variable factors, which affect the coke consumption per ton of pig iron and the quality of iron directly, but are capable of anticipation and calculation. The coke hardness is a thing apart, and can be treated as such, although it has its chemical actions and reactions to perform in the furnace, apart from its purely mechanical functions. This “ hardness ” can be determined in the Greville Jones coke tester, which shows whether a coke is good, bad or indifferent, from the hardness point of view, for utilisation in the blast- furnace. The tester consists of a drum which revolves at 18 revolutions per minute, with two angle-bars fixed inside to turn the coke over; there is a hand-hole for inserting and extracting the coke sample, and an indicator to note the revolutions. To make the test, about 56 lb. of lump coke are taken and dried on hot plates for 20 hours. Of this, 281b. are weighed out and placed in the drum, which is then revolved for 1,000 revolutions at 18 revolutions per minute. The coke is taken out and riddled over a | in. mesh, and that which remains on the riddle is weighed. The percentage in relation to the original 281b. noted expresses the “ hardness ” of the coke. By closely watching and comparing the furnace drivings with the coke hardness, it is found that there is a very close connection between the two, and that the coke, and that alone, is responsible for the variations in the drivings. The next point on the coke hardness scale at which the drivings commence to fall off lies between 74 and 74J per cent, of hardness; and the experience of the past eight years shows that there will be slow driving and consequent trouble when the hardness falls below that percentage. The author has not been able to trace any additional advantage with coke of a higher per- centage of hardness than 76 per cent., but on plants where a blast-pressure in'excess of 71b. per sq. in. is used or available, it may be found that the benefits derived from a hard coke may accrue to a higher per- centage than that mentioned. When the hardness falls below 74 per cent.'a very marked falling off in the drivings takes place, and the lower the percentage the worse are the drivings. Experience with coke averaging only 70’5 per cent, of hardness has shown that, as a direct result, the drivings of the blastfurnaces have fallen 20 per cent. Effect of Hardness on Coke Consumption. When coke is charged into a blastfurnace it imme- diately comes into contact with the ascending gases, which act upon it in a greater or lesser degree, dependent upon its mechanical condition and the temperature of the gases. Many experiments have been carried out in the laboratory with a view to illustrating this reaction, and it has always been found that the gases have far less effect on hard coke. In one experiment made for the author in the Ormesby laboratory, pieces of hard and soft coke were placed in crucibles containing carbonate of lime which supplied the CO2 and covered with lids and placed side by side in the muffle for 45 minutes. Action of Carbonic Acid on Hard and Soft Coke. Test made at a red heat. 705 degs. Cent. (1,382 degs. Fahr). Hard coke. Soft coke. Grammes. Grammes. Before test—weight of coke... 13’834 ... 11’610 ... ... After „ „ „ „ ... 13’713 ... 11’243 0’121 ... 0’367 Percentage loss... 0’88 ... 3T6 It therefore seems to be conclusively proved that if a coke of over 74 per cent, hardness is used, very little loss occurs at the top of the furnace, but if a coke of below 74 per cent, hardness is used the loss may be very considerable. Again a soft coke is usually very friable, and unless the ovens are situated close to the blastfurnace, so that the minimum of handling is thereby assured, it usually reaches the furnaces in a much smaller form than is the case with hard coke, consequently a greater area is exposed to the action of the gas as soon as it is charged into the furnace. Having therefore commenced its passage through the furnace in a small state, it will become very finely divided before reaching the melting zone. At the Ormesby furnaces trouble was experienced through using soft and friable coke, and even after the coke commenced to improve the drivings of one of the furnaces became so slow that it was feared she was commencing to hang, as the slag could not be got to run. On taking out the front tuyeres and blowing forward for a while to try and clear the forepart, great clouds of fine coke dust were blown out, and when this ceased the front tuyeres were replaced, and the furnace commenced to drive again quite freely, no further trouble being experienced with drawing off the slag. This, though an extreme case, shows that a low coke con- sumption cannot be expected when the coke loses some 10 per cent, or 15 per cent, of its weight within two or three hours of being charged into the furnace, and, on arriving near the tuyeres, is in the form of dust so finely divided, that it actually obstructs the passage of the blast and the tapping of the slag. On the other hand, when a hard coke is being charged, there is only a very small loss at the furnace top; the lumps of coke are larger and less friable, the burthen is kept open, and the blast passes through the furnace with a minimum of resistance, so, when the coke reaches the tuyeres, there is a consider- able body of carbon left to be reduced by the blast, and the gases evolved therefrom are consequently operative on all the materials in the furnace from the tuyeres to the throat. * From paper read before the Iron and Steel Institute.