The President introduced Mr. E. E. Eysenbach, of Columbus, O., who read the following paper on

CYANIDES IN THE GAS AND WASTE PRODUCTS AT COLUMBUS, O.

It seems to be quite customary to begin papers prepared for Association meetings with an excuse. Precaution, I think, against anticipated criticism. Nor can I resist from giving mine. The limited number of results given in this paper is due rather to the fact that our Secretary applied for it at the eleventh hour, than to a feeling that I had done justice to the subject.

The results I do give were made very carefully, and although different from what was expected present conditions as found at our works.

Articles appearing from time to time regarding the great value of the cyanides in our gas first aroused my interest in the subject. Besides, the continually increasing use of the cyanide process for the extraction of gold will always give a good market for these products. The value of Germany's exports along this line also make it appear as if we ought to make some money out of them. However, very little has been done in this country toward their recovery, or in increasing our knowledge on their occurrence, and, as far as I know, no commercially successful plant is now in operation.

The following determinations were made to help towards ascertaining the cause of this condition of things. Qualitative tests, made at various times and at various points in the scrubbing and condensing apparatus, never indicated the presence of either ferro or sulpho cyanides in the gas, but the cyanides were always present, as shown by their characteristic test.

Quantitative determinations were then made of these with results as shown below. The average yield of gas per ton of coal was about 9,800 feet, and duration of charges at our works is four hours.

First-Gas tested at inlet to washer scrubber—

Test No. 1.... 307 HCN, in grains per 1,000 feet.

Test No. 2... 332

Second-Gas tested at inlet to purifiers

Test No. I.... 319 HCN, in grains per 1,000 feet.
Test No. 2.. 298

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This is equal to about 3,000 grains of cyanogen per ton of coal carbonized. The low yield is probably due to four hour charges,

as the largest amount of cyanogen is given off during the end of the charge.

Determinations were then made for ferro-cyanides on samples of two different oxides. The amount of sulphur in them gives a fair idea as to the amount of work the material has done. It was made up at the works from oxidized cast iron borings and sawdust. It has been in use about one year, and is still doing good work.

Even if this material is kept in use until it contains 50 per cent. of sulphur, the percentage of Prussian blue can scarcely be expected to reach a point where it would pay to work it.

Two tests were then made to determine the amount of cyanogen left in the gas after leaving the oxide purifiers.

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Test No. 1..... 47 HCN, in grains per 1,000 feet. Test No. 2..... 39 Although these tests are rather limited in number, in a general way I would draw these conclusions:

First Practically all the cyanogen compounds reach the purifiers.

Second-In order to recover the cyanides we must either treat the scrubbed gas or the spent purifying material.

Third-A higher percentage is necessary before the cyanides could be extracted economically.

We have paid no attention to the subject whatever until recently, and may have thrown away material of much better quality in this respect.

I would like to have presented something of more practical value to this Association; that is, I wanted to get more encouraging results to hold up as an incentive for others to experiment along this line. I feel, however, that others may be getting results, and that hints from them will help us.

DISCUSSION.

THE PRESIDENT-Mr. Eysenbach certainly has given a good deal of careful study and work to this paper. It assuredly will be of interest to hear it discussed.

MR. GIMPER-Did Mr. Eysenbach test the hydraulic main. liquor for cyanide?

MR. EYSENBACH-I did not.

MR. GIMPER-It has always been my understanding that the hydraulic main liquor is prolific in cyanides.

MR. R. M. ATWATER-Perhaps that which I have to say may not be of any interest, as the process for the recovery of cyanides in the field in which I am interested is not precisely the same as yours, since it is the retort coke oven, and not the gas retort. We, however, have in our work made some determinations along similar lines to those followed by Mr. Eysenbach, and, while not expressing it in just the terms that he uses, I may say we are able to recover from 1% to 134 pounds of an alkaline cyanide, expressed in terms of ferrocyanide, from a ton of coal, which it is calculated will give profitable results. Of course, in our process we have the advantage of continuously through the year handling comparatively large amounts of coal. The conclusion is clear on our part that in carbonizing 100 or even 200 tons of coal per day it is not profitable to recover the cyanides, but in handling 500 or 1,000 tons of coal per day there is profit in such working. Replying to the question of Mr. Gimper I would not be surprised to find the amount of cyanides in the liquor from the hydraulic main greatly in excess, even to three or four times the quantity found in the ordinary washer.

THE PRESIDENT-I think Mr. Warmington has had experience in recovering cyanides.

MR. WARMINGTON-Experience, but little else. We have tried to get Prussian blue, and although we expended considerable money in our experiments, the latter were by no means successful. The cyanide compounds will be found in greatest quantities in the hydraulic mains and in the ammoniacal liquor.

MR. DOHERTY-I do not want to interrupt the discussion, but, for fear it may close before another opportunity presents itself, I move that the Association appoint a committee to consider this subject, the committee to report at our next meeting. I think the paper of Mr. Eysenbach is a very creditable one, but I wish he had gone into the subject more fully. It is something I wanted. to study, but have not had time to take it up. Indeed, I do not know anything about it practically.

THE PRESIDENT-The Chair will entertain that motion immediately after the discussion.

MR. FERRIER-Can Mr. Eysenbach inform us what proportion of cyanides is found in European gas works?

MR. EYSENBACH-I would say from 8 to 15 per cent.

MR. FERRIER-How do you account for the difference?
MR. EYSENBACH-I can not account for it.

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MR. GIMPER-Variations in the quality of coal might account for the difference.

THE PRESIDENT-Will Mr. Lynn give us some information on this subject?

MR. J. R. LYNN--I have never made any special investigation, but it occurs to me that the heats carried on the benches will to a great degree determine the quantity of cyanides recoverable; the higher the heats maintained the greater will be the quantity that may be recovered.

MR. EYSENBACH-I would like to add that the amount of work done by me, and from which I drew my conclusions, was limited. I did not have time to get a large number of results, but the results which I did obtain, and have given, were from carefully made tests, and I think they are correct.

MR. HAYWARD-I would suggest that, in following up this subject, Mr. Eysenbach secures all the samples of oxide he can obtain. I have had samples sent me from time to time, one of which I particularly recall. It was a specimen from a New England works, in Massachusetts. The consignor in writing about it said he had turned his gas works into a Prussian blue factory and would like to know how he did it. I find that the samples from different works vary considerably; in fact, that no two agree. Some years ago I was interested in this subject. Knowing the high price of cyanides, the large importations made to this country from the other side, and the large quantity made over there in the gas works, I thought possibly something could be done in that direction in this country. I suggested to a chemist who was going to the other side that if he would look into the matter in England and Germany I would gladly pay his expenses. He eventually sent me a report, a summary of which was that we had better, at present, from the developments there, let it alone. That there was not enough in it to pay, and that the prices were continually decreasing. I believe one concern in Brooklyn who took old oxide for the purpose of recovering the sulphur and cyanides, was obliged to give it up, not because enough of these products. were not recovered, but because there was not sufficient profit in it, and for the further reason that the conditions in this country are entirely different from what they are, say in England. The question of freight enters largely. The freight is so large on getting the material back to a place where it can be treated that the operation does not pay. In order to make it profitable, as Mr. Atwater has said, a very large quantity of coal must be carbonized.

MR. ATWATER—Let me refer to one point made by the last speaker. The McKinley tariff, as a rule, increased the rates of duty, but, as a concession to the silver men, the tariff on cyanide of potassium was cut in two; consequently it was more profitable from that time on to import the foreign article than to make it on this side, which largely accounts for the fact that now American works do not find it profitable to produce the material.

THE PRESIDENT-Is there anything further to be said on this subject?

On motion of Mr. Gimper, a vote of thanks was given to Mr. Eysenbach for his paper.

MR. DOHERTY-I now move that a committee be appointed by the Chair to investigate this subject and report at the next meeting.

The motion was seconded by Mr. Wheeler and adopted.

THE PRESIDENT-With the assent of the Association I will not announce that committee until to-morrow morning, as I would like to give the matter consideration by conferring with the members most interested in the subject.

OPENING THE QUESTION BOX.

At the suggestion of a member the Question Box was opened. The Secretary read the questions in this order, the replies being as recorded:

1.

"Does anyone know of the use in this country of Chameroi pipe which has been so extensively used in France?”

MR. DOHERTY-1 have never heard of it. What is Chameroi pipe?

THE PRESIDENT-I do not know. Can anyone answer the question? If not we will pass it over for the present. Perhaps the member who asked the question may give us some information.

2. "What is the best method of supporting and protecting main pipe on bridges?

MR. GIMPER-I do not know what may be the best method, but I tried one which proved very satisfactory. I had a pipe, made of the best boiler iron, 8 inches in diameter, leading across a bridge. To protect it I took the packing that we use for joints and packed it very closely. Over that I put tarred paper and tarred felt, over which I put bagging, sewed it up, and then painted it over thoroughly. It made the best covering that I have had in my experience.