US1006877A - Metallurgy of zinc. - Google Patents

Description

A.L.J.QUENEAU. METALLURGY 0P ZINC:

APPLICATION FILED JUNE 8, 1911,

Patented 00t.24, 1911.

3 SHEETS-SHEET 1,

A. L. J. QUENEAU. METALLURGY OF ZINC.

APPLICATION FILED JUNE 8, 1911.

Patentd 0012.24.1911.

3 SHEETSSHEET 2.

[IZUtP/Z/Of'i ll zzflesses:

741 6 i%% a I A. L. J. QUENEAU.

METALLURGY 0F ZINC.

APPLICATION FILED JUNE 8, 1911.

Patented Oct. 24, 1911.

3 SHEETSSHEET 3.

ll l l kfsasl W ammo STATES PATENT caries.

AUGUSTIN LEON JEAN QUENEAU, OFIHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO QUENEAU ELECTRIC ZINC FURNACE COMPANY, OF PHILADELPHIA, PENNSYIr I VANIA, A CORPORATION OF DELAWARE.

METALLURG'Y OF ZINC.

I Specification of Letters Patent. Application filed June a, 1911.

Patented Oct. 24., 1911. Serial No. 631,952.

clare the following to be a full, clear, and.

exact description of the invention, such as will enable others skilled in the art to which it appertains to make anduse the same.

In a certain prior application for Letters Patent of the United States, Serial Number 536,791, filed January 7, 1910, I have shown and described a method and apparatus for the extraction of zinc from zinc ores and similar reducible compounds of zinc, by the expedient of supplying the charge to be reduced into a rotary reducing chamber and upon a molten resistor contained therein,

which resistor is maintained, durin the reducing operatlon, at a sufficiently high temperature, by the passage of a suitable electric current, to effect the reduction of the zinc ore or compound and the volatilization of the zinc, which is thereupon recovered in a suitable condenser. I

The present invention relates to improvements upon what is described and shown in my former application for Letters Patent referred to.

Particularly, it consists in a simplification of the furnace structure in some respects, and in certain improvements in effecting the condensation of the zinc vapors.

In the drawings, Figure 1 represents, in longitudinal section, an apparatus embodying my present improvements. Fig. 2 represents a vertical cross-section thereof taken on a plane indicated by the line 2, 2 of Fig. 1. -"Fig. 3 represents a vertical cross-section through the condenser taken on a plane indicated by the line 3, 3 of Fig. 1. Fig.- 4 indicates the end view, partly in section and on a larger scale.

Similar letters of reference indicate similar parts throughout the several views.

As in my former application, the reducing chamber is of the rotary type, that is, it is a chamber adapted to be rotated. continuously or intermittently in one direction,

tumbling action. It is provided with a molten resistor D, which may be of molten metal (such as iron containing phosphorus, in the preferred proportion of 12%, by weight, so as to impart to it high resistance), or of molten slag, which I prefer in practice, and which may consist of a slag left over from a former operation in the chamber, or that may be supplied from any suitable source. When slag is used as a resistor, it should be highly fluid, and, in making up ,the charge of ore to be reduced, care is to be taken that it shall also be so compounded as to produce a highly fluid or alternately in opposite directions, so as to sub ect the contents of the chamber to a slag, to which'end, if need be, some additional slag-formin ingredient 'may be added, as, for instance, uor spar, or phosphoretic slag from-an open hearth steel furnace or the like.

The reducing chamber is provided with an outer metallic shell k (preferably of low carbon steel), which may be provided with tire rings d secured thereto, which rings rest upon flanged rollers e, the axis of the chamber being usually horizontal. The shell is further provided with a band gear which constitutes an element of a variable drive, adapted to be actuated from a variable speed motor, so that the number of revolutions or oscillations of the chamber may be readily varied. The rotary chamber is provided at one end with a metallic plate It, having a hub projection m which, in turn, is adapted to be closed by an end-plate E. Near the outer edge of the plate It is a series of apertures through which pass a corresponding series of bolts 2'. These bolts likewise pass through a stationary flange 7' of the shell and through the slidable ring Z.

They are provided with screw-threads at their ends and with adjusting nuts and washers, asshown. Springs m, are'inter: posed between the flange 7' and ring l and encompass the bolts, so that the plates it may have a capacity for independent movement, to correspond to the effects of heat expansion, but will, nevertheless, be held 'in strong elastic adjustable contact 'with the end of the chamber. The bolts are held' out of electrical contact with the plate It, the

flange j and the ring 1- through which they pass, by means of insulating sleeves, as

shown, and the springs m rest against in:

sulating washers and are out of electrical contact with the flange j and the ring Z, so that no electric current shall pass through the springs, to afl'ect their temper or resiliency. The end-plate h is provided with a I shell is by means of the same instrumentalicase may be.

ties that are used for connecting the plate It to the shell. The plate h, however, is intended to be, at all times, electrically connected to the shell 70, and this is effected through the instrumentality of a series of spring metal plates G connecting the plate h with a flange on the shell is, as shown. The plate It is accordingly held in strong electrical adjustable contact with the end of the chamber, regardless of the effects of heat expansion. .The plate k may be conveniently provided with suitable recesses M adapted to be cooled b air, or water, as the The ot er lead 2 from the external circuit (when a direct or a singlephase alternating current is employed) may contact with the shell is through the inter-' bonaceous binder, in brick or block form, the

, bricks or blocks having first been suitabl baked at a sufliciently high heat to drive 0 their volatile constituents and to convert them into conductors of the first order. Exterior to the courses C are the graphite end linings '11 adjacent to the. end-plates h, it. With this arrangement, the circuit is completed from the lead 3 to the plate It, thence by the adjacent graphite end lining a and the conducting courses C, to the fluid con- 7 ductor D, thence to the conducting courses O at the other end of the chamber, the graphite end lining a at said end, the plate and the bow-spring conductors G, the

a if shellk, and the ring (2, to the opposite lead z of the circuit.

At its middle portion, the inner lining'of the furnace is preferably somewhat wider, so as to form a well, of greater or less depth, E, for the more convenient assembling of the heavier metals that may bepresent'in the charge. The tubular hub projection w is provided with a magnesite, brick or chromite' brick lining, which is continued beyond the plate h, thereby likewise form-..

The condenser, in the form shown in thedrawings, consists of a shell is, having at one end an annular angle flange N, whereby it is bolted to the end-plate h. At its opposite end, the shell is is sup orted from the same plate h by means 0 screw-threaded 1 rods. f, provided with turnbuckles is, for" adjusting their tension.-

At the end proxlmate to the course a the condenser is provided with a course 0 of magne'site brick or chrome brick, likewise flaring in the same general direction as the courses a 6 and spaced at suitable intervals along the length of the interior of the condenser are arranged the battle dip partitions-L, which may conveniently be made up in sections, as indicated in Fig. 3, so as to be the more readily removable and insertible. These partitions are provided with a series of apertures 0, as shown, and also with a central aperture 39, the latter being provided so as to afi'ord access to the exit-opening s from the reducing chamber, in case that opening should become clogged. The partitions L are held in place by intermediate courses 0 of slightly lesser internal diameter, and the extreme outer end of the condenser chamber; is conveniently lined with a refractory lining A. The combustiblegases, such as carbon monoxid, escape from the condenser through the prolong B together with any zinc vapors that may poss'ibly have escaped condensation, and if so I desired, the prolong may communicate with any suitable receptacle for the recovery of such vapors in the form of zinc oxid or of blue-powder. Finally, the condenser is provided with means for regulatinglit's temperature, consisting of a pipe P having a refractory outer lining (i if necessary, and a hollow interior into which enters a pipe 0 which is supplied either with cold water or air, or hot water or air, as the case may be, through the supply pipe 6. By this expedient, the temperature prevailing within the condenser may be carefully re lated, the cooling or heating fluid passing out through the exit pipe (1 The condenser is provided with a suitable tapping aperture 8, and the reducing chamber itself 1s provided with a tapping a erture closed by the metallic pulg e and t e removable refractory plug 0.

' molten lead admitting the zinc ore charge, the furnace is heated preliminarily. This heatifig may be effected, if desired, by a gas or oil flame, or by admitting into the furnace a body of or other metal of low melting assing the electric current through the urnace while subjecting it to a slow movement of rotation. When the furnace lining has attained the necessary temperature, the furnace is stopped and the lead or other like material is tapped off. A known amountof resistor, preferably melted before it is inserted in the furnace, is then introduced, sufiicient to reach the level desired, and the charge of mixed zinc ore and coke or otherreducing agent is fed in.

The charge may consist of a mixture of zinc ore and coke, wherein the coke is but slightly in excess of that theoretically required for the reduction of the ore. This mixture is preferably preheated to ashigh point, and

a temperature as the coke will tolerate without ignition (say, to a temperature of about 500 (1), by placing it in a rotary furnace of the muffled type, heated exteriorly by the products of combustion from any suitable heating furnace. The rotary furnace referred to contains a suitable number of steel balls and therefore serves as a ball mill. The rotation of the ore and coke mixture during the heating and grinding operation in the ball mill furnace serves to insure the highest possible homogeneity of the mixture and the uniform heating-of the individual particles. The charge is then transferred to the reducing chamber and deposited upon the fluid resistor therein, whereupon the reducing chamber is then closed and slowlyrotated, the electric current maintains the necessary thermal conditions for the reduction of the ore and the volatilization of the zinc.

The gaseous and'volatile products of the reducing operation enter .the condenser, wherein is already located arelatively large body I of molten zinc, which has been previously introduced therein. As the condenser slowly revolves, with the reducing chamber, (say about 1 revolution in from 8 to 10 minutes) the upper and hotter parts of the partitions L pass through the molten zinc and are cooled thereby, this cooling being facilitated by the presence of the openings which increase proportionately the cooling and condensing surfaces. Furthermore, the frictional contact of the partitions with the vapors, and any zinc that may adhere to the partitions, facilitate the condensing effect. To these factors, and to the large --surface contact of the zinc vapors with the molten zinc in the bottom of the condenser and the baffling effect of the partitions, likewise contributes the careful regulation of the temperature of the condenser, all combining to bring about an effective condensation of the zinc vapors in'the form of metallic zinc, which joins the main body of zinc I in the condenser. When a sufiicient quantity of zinc has accumulated, the rotation of the apparatus is temporarily interrupted and the re uisite amount is tapped from the openings .9 leaving a remaining body sufficient to carry on the operation when the rotation of the apparatus is resumed.

The lining of the condenser as well as the material of the partitions L may conveniently consist of Dixon graphite, compounded with clay, so as to make substantially the same material that is. employed for the ordinary graphite crucible. This material is preferred because it is tough, smooth, easyto clean, resistant to shocks without breaking, and for the further reason that it keeps the metal sweet. The I condenser has the advantage of relatively large volume, large cross-section, and large contact surface to the passing vapors, as wellas large contact surface of zinc for said vapors, and, inasmuch as it is provided with means for carefully regulating the temperature, all of the conditions are present for obtaining a satisfactory condensation of the zinc, while permitting the free escape of the carbon monoxid and other like gases. In fact, it will, of course, be evident that the condenser may be employed generally in connection with reducing chambers for the treatment of zinc ores and compounds, other than the reducing chamber herein shown and described. I Having thus described my invention what I claim is:

1. An electric furnace for the metallurgy of zinc ores and compounds, comprising areducing chamber, a fluid resistor therein, and, means for heating said fluid resistor electrically, the electric current being introduced into the fluid resistor and taking its exit therefrom through the intermediacy of a portion of the furnace lining consisting of a mixture of refractory material and carbonaceous material constituting an electrical conducting body ofthe first order; substantially as described. V

2. An electric furnace having a reducing chamber provided with a longitudinally-expansible lining, in combination with a conducting end plate held in yielding relationship thereto through the intermediacy of an interposed refractory conductor; substantially as described.

3. An electric furnace having a reducing chamber provided with a longitudinally-ex pansible lining, in combination with a conducting end-plate held in yielding relationship thereto through the intermediacy of an interposed refractory conductor, said conductor consisting in part of an annular course of refractory conductingblocks extending within the furnace interior, and in part of an outer. annular courseof refractory conducting blocks intermediate thereof and the conducting end-plate; substantially as described.

4. An 'electric furnace having a reducing chamber, provided with a longitudinally-expansible lining, and with yielding conducting end plates, a fluid resistor within the chamber, andrefractory conductors 1n electric connection with the end plates and bridged by the fluid resistor; substantially as described.

5. An electric furnace for the metallurgy of zinc ores and compounds, comprising a rotatable reducin chamber, a fluid resistor therein, means or heating said fluid resistor electrically and a condenser communicating with the interior of the rotatable reducing chamber b means of a flaring opening, thereby quic y expanding the vapors as they enter the condenser; substantially as described.

6. An electric furnace for the metallurgy of zinc ores and compounds, comprising a rotatable reducing chamber, a fluid resistortherein, means for heating said fluid resistor electrically, and a condenser rotating with the reducing chamber, said condenser being provided with transverse partitions, which, as the condenser rotates, pass through the zinc in the bottom of the condenser and are cooled thereby; substantially as described.

7 An electric furnace for the metallurgy of zinc ores and compounds, comprising a rotatable reducing chamber, a fluid resistor therein, means for heating said fluid resistor electrically, and a condenser rotating with the reducing chamber,said condenser being provided with transverse partitions, said partitions having openings therein, which,

as the condenser rotates, pass through the zinc in the bottom of the condenser and are cooled thereby; substantially as described.

v8. An electric-furnace for the metallurgy of zinc ores and compounds, comprising a rotatablereducing chamber, a fluid resistor therein, means for heating said fluid resistor electrically, and a condenser rotatin with the reducing chamber and provide with means for regulating the temperature prevailin in the condenser, said means consisting 0 a temperin pipe entering the condenser and supplie' with a tempering fluid; substantially as described.

9. An electric furnace for the metallurgy of zinc ores and compounds,-comprising a rotatable reducing chamber, a fluid resistor therein, means for heating said fluid resistor electrically, a condenser rotating with the reducing chamber and provided with transverse baflling partitions, and a tempering pipe entering the condenser axiall and supplied with a tempering fluid; su stantially as described.

10. An electric furnace for the metallurgy of zinc ores and compounds, comprising a rotatable reducing chamber, a fluid resistor therein, means for heating said fluid resistor I electrically, a condenser a series of perforated disk partitions spaced apart in said condenser, and a tempering plpe entering said condenser axially and supplied with a tempering fluid; substantially as described. Intestimonfywhereof I aifix my signature,

in presence 0 two witnesses.

AUGUSTIN LEON JEAN QUENEAU.

. Witnesses:

f; .l WM. JAY TURNER,

- A. E. MAHAN.

Images