US1565928A - Zinc condenser - Google Patents

Description

Patented Dec. 15,1925.

UNITED STATES 1,565,928 PATENT oFFica.

HARRY A. GRINE, OF CLARKSBURG, WEST VIRGINIA, ASSIGNOR TO THE 'GRASSELLI CHEMICAL COMPANY, OF CLEYELAND, OHIO, A CORPORATION OF OHIO.

ZINC CONDENSER.

No Drawing.

'To all whom it may concern:

larly directed to an improved condenser for use in the retort or muflle smelting of oxidized zinc ores to produce metallic zinc, the ,principal object of the invention being the provision of a condenser of this type and purpose which shall have a high content of zinc-bearing material and low clay content. A further object of the invention is the provision of such a condenser which ,shall have a greater heat conductivity, greater condensing efficiency, and shall be capable of re-use when broken up, with a minimum of low Zinc-bearing materials in the broken condenser product which is to be re-ch'arged. Other objects of the invention will appear hereinafter. To the accomplishment of the foregoing and related ends, said invention,

then, consists of the means hereinafter fully described and particularly pointed out in the claims, thefollowing description setting forth in detail one method and one product exemplifying my invention, such disclosed procedure and productconstituting, however, but o'neof various applications to the principles of my invention. a The present practice of retort or muffle smelting of oxidized zinc oresfto produce metallic zinc involves the introduction of the zinc ores and reducing fuel intoa retort or mufile which is: mounted in a furnace chamber in which the temperature is maintained at'the proper heat for reduction of the ore. Condensers are set in the mouth or open end of the mufiles of retorts and luted thereto with finely-ground anthracite culm which forms a joint between retort and condenser which is impervious to "zinc vapors under the low pressure within the -retorts. These condensers project without the fur nace chamber and cause sufiicient dro in temperature of the zinc vapors issuing rom composition which is high Application filed April 3, 1924. Serial No. 703,979.

the retorts to condense them and also serve to retain the metal after condensation until drawn. The present condensers consist in composition ofabout nine parts by volume of burned clay or grog to seven parts of raw plastic refractory clay. Neither of these materials contain zinc in smeltable quantity, only a very small per cent being contained in reclaimed retort or condenser material used as grog in the making of new condensers. The burned clay may be either new material used for the first time, or it may be all or partly burned clay material recovered from broken retorts or condensers which have been used.

At the end of each days operations the crmdensers are removed from the mouth of the retorts'ormuiiles to allow the removal of the residues from the muliics, after which the retorts are charged with new ore and fuel. 111 removal a number of the condensers are broken, and certain condensers are discarded because of the accumulation of 'zinc oxide, zinc dust or blue powder and metallic'zinc on the inside ofthe condenser, which material has a higher melting point than the metallic Zinc and gradually covers the condenser with a coating up to one inch in thickness. The broken and discarded condensers are broken up and the condenser man selects the portionswith the heaviest deposits of zinc thereon, these selected portions being broken into small pieces and then recharged into the furnace along with the new ore and fuel. In this way a certain amount of the deposits on the condensers are saved for the recovery of zinc contained.

My improved condenser is formed ,of a in zinc bearing materials and relatively low in refractory clay and other low or non-zinc-bearing materials, which allows the condensers after use to be completely broken upa'nd recharged, with a saving of practically all of the residues on the condenser and of the zinc content in the condenser itself. My improved condenser may be formed of a mixture containing approximately 80 per cent to 85 per cent of zinc-bearing material, assaying 25 per cent or more zinc, such for example as broken used ore condensers, calcined Joplin ore, which contains about 68 per cent zinc and a small amount of finely pulverized plastic clay as a' bonding material. I use these materials in the proportions of about 45% of the broken used ore condenser, 45%

of new ore and 10% of plastic bonding clay.

A condenser mixture formed of these materials will have approximately 52% or 53% zinc content before use and a zinc content after use for seven or eight days of about Various bonding materials may be used, such, for example, as fire clays or bentonite, and these and others have been found entirely suitable for this purpose.

After condensers of my composition are discarded they are broken up to pass a fourmesh screen, and this crushed material is then mixed with ore and charged into the furnace, thus returning to the furnace all of the zinc material.

In making m condensers I may use some of the discarde condenser material crushed to pass a four-mesh screen, which is then thoroughly mixed withcalcined zinc ore or zinc ash, or materials of a similar nature, which has been crushed to pass a QO-mesh screen, or may use straight zinc ore, and then mixed with plastic clay or other bonding materials, which have been crushed to pass a 40 to (SO-mesh screen. These various materials are then pugged through a wet mixing pug mill in the usual manner and allowed to stand for several days and then re-pugged, after which the material may be molded into condensers in the machine commonly used for this purpose. After molding the condensers are placed in a drying room and baked at a temperature of from 100 to 140 F. for 10 to 15 days, and then given a second baking at a higher temperature of from 150 to 175 F. before use.

My condensers have a higher strength than those now in use, and in this way effect a considerable saving, as less are broken in handling. They also have a greater heat conductivity since the walls may be thinner because of the greater strength of the material. In addition, these condensers have a higher condensing efficiency because of the greater heat conductivity of the material and the thinner walls of the condenser. The use of thinner walls effects a saving in the breaking up of the condensers after use for subsequent recharging and also in concentrating costs where wet concentration or hand chipping and selection of condensers is practiced.

In addition to the above advantages I effect a considerable saving in zinc, which is in present practice lost because of pieces of condenser discarded and not recharged, and a greater efficiency in thefurnacing operation because of the absence of considerable amounts of refractory materials which are unavoidably included with the Zinc from the broken-up condensers under the present practice and availability of the retort capacity, which would be occupied by such barren material, for the smelting of zincbearing material.

Other forms may be employed embodying the features of my invention instead of the one here explained, change being made in the form or construction, provided the elements stated by any of the following claims or the equivalent of such stated elements be employed, whether produced by my preferred method or by others embodying steps equivalent to those stated in the following claims.

I therefore particularly point out and distinctly claim as my invention 1. A composition for zinc condensers comprising broken zinc condenser, zinc ore and a refractory bonding material.

2. A composition for zinc condensers comprising approximately 80 per cent zinc bearing material consisting of equal parts of broken zinc condenser and zinc ore and 20 per cent refractory bonding material.

3. A composition for zinc condensers comprising equal parts of broken zinc condenser and zinc ore, each having a zinc content in excess of 60% and a small amount of plastic refractory clay.

4. A composition for zinc condensers comprising equal parts of broken zinc condenser and zinc ore, each having a zinc content in excess of 60%, and about 10% of plastic refractory clay. 7

Signed by me, this 24 day of March, 1924.

HARRY A. GRINE.