EARLY PROCESSES OF SALT MAKING

Only in the very early days was salt made in the kettle. The next development was the pan-some 20 to 30 ft. wide, 100 to 150 ft. long, and 12 to 18 in. deep. They were direct fired, and the salt was raked out by hand. Little or no salt is now made in this apparatus, though up to a short time ago old salt pans were still standing along the St. Clair River.

With the growth of the lumber industry came the grainer, a distinctly Michigan type of salt-making apparatus. This is a tank 18 to 24 in. deep, 12 to 18 ft. wide and 100 to 120 ft. long. In this are submerged a number of pipes through which passes steam (or hot condensed water from previous grainers). The brine does not boil, but merely evaporates slowly. The size of grain depends on the rate of evaporation, which in turn depends on the temperature of the brine, as the coils are heated by live steam, exhaust steam, or condensed water. The salt grows on the surface as floating aggregates of hopper-shaped crystals. These fall to the bottom and are raked out by hand, or more often by mechanical rakes actuated by hydraulic cylinders. The grainers are made of wood, steel or concrete. In 1887 the first vacuum pan was introduced into Michigan, and there are now a number of plants using single or multiple effect vacuum pans. This process gives a fine, uniform, compact grain, very well suited for table purposes. The coarse and less compact grainer salt occludes mother-liquor and is less pure.

THE ALBERGER PROCESS OF SALT MAKING Michigan has the only plant in this country using the Alberger process. In this process the brine is heated in steps to about 350 deg. F., at which point the solubility of calcium sulphate is very low. The brine is then led through cylinders filled with stones, where the gypsum is deposited, the supersaturated solution being seeded by crystals adhering to the stones; and then the brine is led to the "evaporators." These are nothing but cylinders with an opening near the top where the superheated brine is allowed to escape. The flash or self-evaporation which takes place when the pressure is relieved causes the formation of seed crystals. The hot brine with these seed crystals is blown out into large shallow pans. Surface evaporation causes the crystals to grow till they fall to the bottom and are raked to a well, whence they pass to a centri

fuge. The brine overflowing from the pans is returned to the heaters. This process gives a very open and porous grain, but far finer than the grainer salt. It is almost entirely used for table and dairy purposes. No account of the Michigan salt industry is complete without mention of the Manistee Iron Works. They introduced the vacuum pan into the salt industry; and Manistee pans are found not only in most of the vacuum pan plants of the State, but in many salt plants throughout the country.

Table I gives a list of some Michigan salt plants, and Table II gives the Michigan salt production as compared with that of the total in the United States for the years 1914 to 1917.

BROMINE AND CALCIUM CHLORIDE

The brines of the Saginaw Valley contain many impurities, chiefly bromides and calcium and magnesium salts. The Dow Chemical Co. of Midland has for years been by far the largest producer of bromine in the United States. The brine is electrolyzed to give a gas consisting of chlorine and bromine, and this gas is used to displace the bromine from the brine. Calcium chloride is made by the Saginaw Chemical Co. Bitterns discarded from salt grainers are further concentrated, which throws out much sodium chloride. The solubility of sodium chloride decreases rapidly as the concentration of calcium chloride increases. The remaining mixture of calcium and magnesium chlorides is concentrated till it solidifies when run into drums. Large quantities of calcium chloride are also obtained as a by-product in the Solvay process.

ALKALIS, ACIDS AND HEAVY CHEMICALS Because of the salt deposits, Michigan has an enormous alkali industry. In the Detroit district are the Solvay Process Co., the Pennsylvania Salt Manufacturing Co. and the Michigan Alakali Co. The Dow Chemical Co. at Midland also produces alkali. The Solvay Process Co. and the Michigan Alakali Co. use the Solvay process; the others make electrolytic caustic. The Pennsylvania Salt Manufacturing Co. uses the Gibbs cell; the Dow Chemical Co. a cell of its own.

Sulphuric and nitric acids are made by the Detroit Chemical Works, which also makes alum. The electrolytic plants of course make either chlorine or bleach according to the demands; though the Dow Chemical

3

Single, double or triple

10 ft.

Michigan's contribution to the potash situation has been from two sources-wood ashes and beet sugar waste waters. This latter is mentioned in connection with the sugar industry. In the hardwood districts there are reported about 25 small producers of potash salts from wood ashes. The ashes are packed in shallow tubs, leached, and the resulting solution concentrated till it .solidifies. The product is mainly carbonate; if lime is added with the ashes it is largely hydroxide. Of some 32,500 tons of K,O reported as produced in the United States in 1917, wood ashes (in which Michigan has 25 out of 49 producers) are credited with furnishing 621 tons, and beet sugar waste waters (where Michigan has one out of 5 producers) with 370 tons.

IRON AND STEEL

Though Michigan is the second largest producer of iron ore in the United States, the iron actually smelted is very small in amount. The Marquette, Gogebic and Menominee ranges, lying mainly in Michigan, produce about 25 per cent of the country's total output of ore and about 30 per cent of the output of the Superior district. Michigan is only about seventh in pig iron production, having only 14 blast-furnaces. The State has no steel plants, though there are steel foundries having one or two open-hearth furnaces apiece. Most of the blast-furnaces are connected with the hardwood distillation industry, and serve as an outlet for the charcoal. Detroit has three furnaces-two at the plant of the Detroit Iron and Steel Co. and one at the plant of the Detroit Furnace Co.

State has some of the largest copper and brass mills in the country, including the Detroit Copper & Brass Rolling Mills, the Michigan Smelting & Refining Co., the Michigan Copper & Brass Rolling Mills.

СОКЕ

The State possesses two coke oven plants, neither primarily connected with the iron industry. The ovens are at the plants of the Solvay Process Co. and the Michigan Alkali Co.; and both plants use the ovens as a source of ammonia. The coke goes to the blastfurnaces in Detroit, to the lime kilns of the alkali process, or is sold for domestic consumption.

The Solvay Process Co. obtains its ammonia from the Semet-Solvay Co., which operates 175 Semet-Solvay ovens. The latest bank of these are equipped to burn producer gas, as under a heating value specification so much gas can be sold to the city of Detroit that not enough remains to heat the ovens. All the newer ovens are regenerative, in contrast with the older design of the Semet-Solvay oven, which was recuperative. The Michigan Alkali Co. has 30 United-Otto ovens.

COAL AND PEAT

A large area in the central part of the State contains coal. The deposits have been worked more or less since 1835, but the industry did not develop till 1897. Recently the production has been about 1,000,000 tons per year. The coal is bituminous, dry and non-coking, and generally of a lower grade than the Eastern coals with which it has to compete. In 1916 there were reported 22 mines.

remains, however, as a possible fuel when either coal is so high as to make it available, or satisfactory methods are found for its utilization.

BEET SUGAR

Michigan is almost the home of the beet sugar industry in the United States. Certainly the industry took hold here in a very healthy manner and mills were built more rapidly in Michigan than in any other State. As the value of irrigated lands and the favorable climate of the Western States began to be appreciated, Colorado and California passed Michigan, but Michigan still remains one of the principal producers of beet sugar. Table IV is taken from the U. S. Department of Agriculture Yearbook, 1917.

The drop from third to fourth place in 1916 was due not only to the falling off in the Michigan production, but to the rapid rise of Utah as a beet sugar State.

The beet mills in the State are shown in Table V.

This shows the State to have a total capacity of 15,000 tons of beets per day. With a campaign of 70 days this calls for a little over 1,000,000 tons of beets for the campaign. This means that the industry was working to capacity in 1915; but, with a campaign of 50 days, only about two-thirds capacity in 1916 and 1917.

Many mills run the Steffens process, and many dry their pulp for the manufacture of cattle feed. Since the mills are all older than most Western mills, the newer equipment (such as labor-saving filters, etc.) found so frequently in the Western mills has not yet been generally introduced.

Two interesting developments in connection with the sugar industry are the plants of the Michigan Chemical Co., at Bay City, which ferments beet molasses to alcohol; and the plant of the Columbia Sugar Co. which has been evaporating its Steffens waste water for the recovery of potash.

WOOD DISTILLATION

Michigan ranks in the first two or three States in the quantity of wood distilled. This is largely centered in the Upper Peninsula, though there are some wood distillation plants in the Lower Peninsula. E. I. du Pont de Nemours & Co. has plants at Bay City and Brayling. The Cleveland-Cliffs Iron Co., the Charcoal Iron Co. of America and the Lake Superior Iron & Chemical Co. all operate plants in the Upper Peninsula for the distillation of wood. Michigan plants produce finished acetone, wood alcohol and gray acetate of lime. In connection with many of the plants are also charcoal blast-furnaces.

PAPER

Michigan is a very important paper State. The district around Kalamazoo and from there west to Lake Michigan is the most important book paper district in the country. At one place or another in the State nearly every kind of paper is made, but the principal output is book paper.

There is no mill in the State making soda pulp. Sul

process. The reworking of old paper is a very important feature of most of the mills. There are boxboard and strawboard mills, one concern makes parchment papers of all sorts, and another makes a specialty of unusual finishes and colors for covers, photograph mounts, etc. There are 30 to 35 paper mills in the State.

One interesting feature of the paper industry is that it is the second industry in the State to unite in maintaining co-operative research. The Michigan Gas Association has for many years maintained a research laboratory and fellowship funds at the University of Michigan, and in 1915 a group of paper manufacturers united to found such an arrangement for the paper industry. The war has greatly interfered with the plans, as might be expected, so that not nearly as much has been accomplished as in the same length of time had conditions been normal.

DYES AND ORGANIC CHEMICALS

The State has two dye plants-the Holland Aniline Co. and the Dow Chemical Co. The Holland Aniline Co. confines itself to a few dyes, including methyl violet, sulphur browns and blues, and bismark brown. The Dow Chemical Co. has long been a producer of chloroform, the manufacture of which was indicated by its production of chlorine in connection with the bromine process. From this, at the beginning of the war, it was only a step to other simple organic chemicals, then the more complex ones, and finally dyes.

PAINTS AND VARNISHES

The State contains two of the largest paint and varrish plants, together with a number of smaller ones. The Acme White Lead & Color Works and Berry Bros., both of Detroit, are among the most important plants in the country in their respective lines. There are also the Boydell Bros. White Lead & Color Co., the Detroit Graphite Co., the Detroit White Lead Works and the International Color & Chemical Co.

TANNING AND TANNING MATERIALS

There is a large number of tanneries all over the State. All kinds of leathers are made-sole leathers, belting, harness, as well as uppers and fine leathers. Chrome, oak, hemlock and tropical extracts are used.

The Michigan Tanning & Extract Co. operates a number of plants, mainly in the Upper Peninsula, for the manufacture of tanning extracts from hemlock bark. The bark is leached in open tanks, and the extract concentrated in multiple effect evaporators.

OTHER ORGANIC INDUSTRIES

The U. S. Rubber Co. has a plant in Detroit-the Morgan & Wright plant-making rubber tires of every description. The manufacture of pharmaceutical products is represented by Parke, Davis & Co., the Fred

erick Stearns Co. and the Digestive Ferments Co., all of Detroit.

The Franck Chicory Co. has several plants through the State for the manufacture of chicory products. The famous plants at Battle Creek making all sorts of special and standard food products must be remembered. There are several plants for the making of condensed milk; and in the southwest part of the State is an important grape district in which are grapejuice plants. And in this connection it is possibly appropriate to mention the Detroit Reduction Co., which takes Detroit's garbage and converts it into fertilizer and grease by the ordinary process of digesting with steam under pressure.

CERAMIC PRODUCTS

Michigan has plenty of clays, but has little in the way of ceramic industries except the manufacture of common brick. There are a few tile plants, but as a general thing the clay-working industries are confined to ordinary building brick.

CEMENT AND BUILDING MATERIALS

In

The manufacture of portland cement in Michigan was begun in 1896. In 1901 the State made 1,000,000 bbl., and was the third largest producer in the country. the last ten years its rank has been fifth to eighth, and it has made from 4 to 5 per cent of the total output of the whole country. Owing to the fact that the important limestone deposits are in the northern part of the State and relatively inaccessible, most of the plants use marl. One plant successfully used the residue of calcium carbonate obtained in making NaOH from Na,CO. This is the Wyandotte Portland Cement Co., operating on the waste from the Michigan Alkali Co. In all, there are 11 active plants making portland cement in Michigan. Table VI gives the Michigan cement production for the years 1913 to 1917 as compared with that of the total in the United States.

Gypsum is always present in salt beds, and is the principal source of trouble in salt making. As one superintendent put it, "When the Lord made salt beds He put some gypsum in so that the salt maker wouldn't have too easy a time." And the small amounts of gypsum that form on the tubes and pipes in salt plants probably represent more time and money than all the gypsum produced as a primary product. However, Michigan has deposits of gypsum that are worked for gypsum as such. Eight plants handle this material, making land plaster, plaster of paris and special forms such as blocks, tile, etc. In the last ten years Michi

gan has been in third or fourth place in this country in quantity and value of gypsum products produced. Table VII gives the Michigan gypsum production for the years 1913 to 1917 as compared with that of the total in the United States.

The State has many deposits of limestone that are worked; varying all the way from extremely high calcium material to dolomites. The sugar industry of the State is almost entirely supplied with high calcium. limestone from the northern part of the Lower Peninsula. The Solvay Process Co. gets its limestone from Sibley, a few miles below Detroit, while the Michigan Alkali Co. brings its limestone from Alpena.

In spite of its many deposits of brick clays, Michigan. has been the first State in production of sand-lime brick since the process was introduced in this country. Michigan produced 26 per cent of the total for the United States in 1917. There are ten or twelve plants in the State, making building brick almost exclusively.

During the war, when every effort was being made to get optical glass with the maximum transmission, so that when made into periscopes and range finders the range of vision might be as great as possible, the principal problem seemed to be to keep minute traces of iron out of the glass. In their search for iron-free raw materials, the glass people finally came to Michigan for their sand. The American Silica Co., operating a deposit near Detroit, was able to furnish a purer sand than any other deposit in the country.

CONCLUSION

The enormous growth of the automobile industry has stimulated every form of metal working and fabricating industries; which means that there is a corresponding demand for the products of the various chemical and semi-chemical processes. For of the chemical and related industries it is especially true that they produce supplies for other industries; in few cases do they make articles which go directly to the ultimate consumer.

With the chemical industries resting on the sure basis furnished by the salt and alkali industries, and the markets assured by the enormous general manufacturing interests of the State, there seems to be a very bright future for Michigan as a great technical State.

An American Chamber of Commerce for Havana A plan is apparently assured to form an American chamber of commerce at Havana similar to organizations of this kind at Paris, London and several other cities.

It is intended to have the work of the organization extend to all parts of the island and to make it a factor of much value in American trade. It is believed that the organization can be of service in matters of transportation, prompt passage of merchandise through

the customs, credits, advertising, etc.

The American Minister has been active in bringing about the new organization, in the interests of which the first meeting was held at the American Legation and attended by more than 100 American citizens. At this meeting, held on July 15, 1919, a temporary organization was effected, and at an early date it is expected to complete the organization and secure suitable quarters and a permanent secretary and such other assistants as may be required. The consulate general is taking an active part in the new project and will be able to render much assistance to it.

Raw Material Resources of Wisconsin

BY W. O. HOTCHKISS State Geologist

ISCONSIN is very close to an average State in

Walmost all particulars. The average State should

have a standing of about 2 per cent, and since there are 48 States Wisconsin has more than her 2 per cent of wealth and population and almost exactly 2 per cent of the area of the United States. In raw mineral reserve products, however, Wisconsin has only about half of the average of the country, its total mineral production being about 1 per cent of that of the United States. Of the important mineral resources, Wisconsin produces no coal, no copper and no precious metals, so, barring these from the list of products of the country Wisconsin has considerably more than the average State in production of raw mineral materials.

ZINC ORES

The principal mineral resources of Wisconsin are zinc, iron and stone. Before the World War zinc ore and iron ore were approximately equal in value, but owing to the great demand for zinc during the war the production of that metal increased nearly four times in value, so that in 1918 the zinc ore produced in this State was worth over $5,000,000. In 1916 and 1917 the value each year was between $7,000,000 and $8,000,000. The metal content of the ore was worth approximately double the value of the raw material. On account of this great development in the zinc industry it is now the largest single item in value of the mineral production of the State. Zinc mines are located

WINDSOR MINE

in the southwestern portion of the State and the district overlaps a little into the adjacent States of Iowa and Illinois.

On the average, the zinc mines are less than 200 ft. in depth, and as the ore comes from the mine it contains considerable limestone, and iron sulphide in the form of marcasite. The limestone is eliminated by

concentration, and the marcasite and zinc sulphide are then sent to a roaster in which the marcasite is given a magnetizing roast and separated from the zinc sulphide in a magnetic separator. During the war plans were made for installing contact acid plants to use the gas from some of the largest roasters. Some of the mines have their own roasters, but many of them ship their ore to central plants, where the marcasite is removed from the zinc sulphide.

The principal production of zinc is from the mines of strong companies. The Mineral Point Zinc Co., a subsidiary of the New Jersey Zinc Co.; the Wisconsin Zinc Co., a subsidiary of the American Zinc Roasting

& Smelting Co.; the Vinegar Hill Zinc Co.; the Frontier Mining Co.; and the Field Mining & Milling Co. produce approximately three-quarters of the total zinc production. Each of these companies operates several mines.

The crude ore before milling varies greatly in zinc content. Some mines will produce as little as 5 per cent of concentrates from the ore, and others will produce more than 20 per cent of concentrates. In some cases, while running on especially rich ore bodies, a much higher percentage of concentrates is recovered. The ore going to the mill is much richer than the Joplin ore.

In the northern portion of the district, in the vicinity of Highland and Mineral Point, some portions of the ore bodies have been altered to zinc carbonate. This finds a ready market at the zinc oxide works of the Mineral Point inc Co. at Mineral Point, Wis., which is one of the largest zinc oxide plants in the United States and draws its ore supplies not only from this district but from the far West and Southwest, and even from Mexico.

IRON ORES

The iron ore of Wisconsin is produced at present from four districts. The largest tonnage comes from the Gogebic Range, which lies in the extreme northern part of the State and extends over into Michigan, where