US2619496A - Solid-liquid reaction processes - Google Patents

Description

Nov. 25, 1952 n R. STANTON 2,619,496

-soLIp-LIQUD REACTION PROCESSES Filed Aug. 7, 1951 3 sheets-sheet 1 EQE@ m z zz llll ` INVENToR. ROBERT STANTON BYX @4MM/ic( 14M H/S ATTORNEYS.

Nov. 25, R952 Filed Aug. '7, 1951 FLUID REACTANT SOL/D REACTANT R. STANTON SOLID-LIQUID REACTION PROCESSES REACTOR 5 Sheets-Sheet 2 EXCESS- FLU/D ROBERT STANTON BY MW@ fwk Nov. 25, T952 R. STANTON SOLID-LIQUID REACTION PROCESSES 5 Sheets-Shaml 5 Filed Aug. 7, 1951 INVENTOR. ROBERT STANTON H/s ATTORNEYS.

Patented Nov. 25, 1952 UNITED STATES PATENT OFFICE 13 Claims.

This invention relates to the reaction processes involving the reaction of lead-alkali metal alloy with a fluid alkylating agent, more particularly to such processes wherein the alloy reactant and the fluid reactant are brought together continuously, and it specifically relates to such processes wherein molten alloy is solidified in coarsely divided particulate form and the so-formed alloy and the fluid reactant are introduced into a reaction zone continuously; the reaction is conducted continuously under high speed agitation induced by fluid propulsion acting upon the solid reactant particles to impart high speed thereto, while the movement of the reactant particles is regulated so that the high speed solid particles undergo high energy collisions.

In the usual processes of reacting lead-sodium alloy with an alkyl halide, the alloy is prepared in a coarsely divided form by grinding or crushing in a device of the ball-mill type.y The milled alloy is then charged into a reactor through a suitable opening. Dangerous conditions may result from the exposure of the alloy to the atmosphere, or by leakage of tetraethyl lead vapor -from the reactor. In addition, the usual processes employ large reaction vessels involving relatively large reaction mixtures, and the reactions are relatively slow and difficult to regulate.

In accordance with the invention, it has been found that such processes can be conducted in a rapid and relatively safe, readily regulated manner, with improved yields. Small reaction mixtures are suitable. The new processes may be conducted in a fully continuous manner and give a highly desirable product.

The objects achieved in accordance with the invention include the provision of a process whereby the reaction of a solid lead-alkali metal alloy reactant and a iluid alkylating reactant may be conducted in a continuous manner in a relatively small reaction zone and residence period; provision of a process for the preparation of alkylated lead by the preparation of a coarsely divided lead-alkali metal alloy and reacting it with alkyl halide in a continuous manner wherein relatively small reaction mixtures of the reactants are involved at any one time; the provision of a process for the preparation of tetraethyl lead by the preparation of coarsely divided lead-sodium alloy and reacting it with ethyl chloride in a continuous manner wherein relatively small reaction mixtures of the reactants are involved at any one time and wherein the particle size of the coarsely divided alloy is reduced as the reaction proceeds; and other objects which will be apparent as details and embodiments of the invention are set forth hereinafter.

2 In accordance with the invention, a molten lead-alkali metal alloy reactant is formed into coarsely divided solid particles, mixed with an alkylating reactant which is in the form of a uidv (desirably by first subjecting to elevated pressure of the fluid, then abruptly reducing the pressure and further mixing) under high speed agitation induced by uid propulsion, and the movement of the reactants is regulated so that the solid particles undergo high energy collisions; all under reaction temperature and pressure conditions.

In an embodiment of the invention, the reaction mass moves through a curved path; and the influence of the centrifugal force will cause the larger solid particles to travel near the outer periphery of the curved path, and the smaller or lighter particles to remain near the inner periphery of the curved path. This favors chemical reaction, and there will also be a reduction in size of the larger particles associated with the high energy collisions in the system. As the reaction proceeds and the solid reactant is reduced in particle size, the reactant and any reaction products move to the inner periphery of the curved path. The more finely divided reactant and any reaction product are removed from the inner periphery and then processed to recover reaction products, unconsumed reactants and byproducts or residues. When desirable, additional residence and reaction time may be provided for further reaction in a succeeding zone or chamber external to the circular reactor.

The process may be conducted in a fully continuous manner, in a partially continuous or intermittent manner, or in a batch type process. The fully continuous process is preferred for commercial operation.

In order to facilitate a clear understanding of the invention, reference may be had to the accompanying drawings in which:

Figure 1 illustrates an arrangement of an apparatus, partially diagrammatical and partially in section, which may be employed for conducting the process of the invention, e. g., in the manufacture of tetraethyl lead.

Figure 2 represents a sketch of the process steps.

Figure 3 illustrates an alternative reaction chamber which may be employed in connection with an arrangement of apparatus similar to that in Figure l.

Figure 4 illustrates an alternative apparatus for subdividing the molten alloy and solidifying it in coarsely divided form.

Figure 5 illustrates an alternative apparatus for preparing the molten alloy.

In Figure 1, a fluid propulsion reaction chamber is represented by 5. This is in the form of a somewhat oval or elliptical loop, having a 180 upper return bend 5A, a similar 180 lower return bend 5B, and straight vertical connecting pipes 5C and 5D. This chamber is in the form of an endless conduit of uniform circular cross section.

A molten alloy supply vessel IDI is positioned so that alloy may be poured therefrom onto a perforated member |62, from which it drops in the form of droplets within a stack |03 into a cooling liquid such as light mineral oil contained in vessel |05. The alloy particles partially solidify by cooling in contact with a rising current of gas, and are chilled in the mineral oil. The temperature of the melt, the distance of fall through gas, the character of the cooling medium, and the like variables are preferably adjusted to provide alloy particles coated with a thin carbonized oil-protective lm. Burners |84 are provided at the lower end of the stack for supplying combustion gases (a nonoxidizing atmosphere) in the stack. Other gases, or even air, could be circulated therein; and passed out of the tap. The vessel |05 is provided with agitating means |06 for keeping the alloy particles suspended in the liquid. A hydraulic ejector |01, energized by a high-pressure stream of cooling fluid, is arranged to continuously feed portions of the slurry from vessel |05 into transfer pipe |03 which delivers it into compartment |09 of the elevated vessel I I0. The liquid level in this compartment is maintained sufficiently high to constitute a seal against backward flow of toxic vapors from the reaction zone. This vessel is divided vertically by the weir plate I I I. The alloy particles settle due to the relatively low velocity in the compartment, and fluid overows the weir plate into the discharge compartment I I2. From there, the fiuid flows by gravity through pipe I I3 into surge tank I Ill. Liquid from the surge tank constantly passes through the cooling vessel IE5, under a constant level or pressure head, either directly through a pipe I I5 (or preferably through pipe I I5 and purication'vessels I 22 containing boiling aqueous hydrochloric acid or the like and |23 containing aqueous caustic or the like neutralizing agent, for removing alkylated lead, as shown). Excess fluid overflows through line ||6 into receiver II'I; from which it is delivered under elevated pressure through pump IIS to activate the hydraulic ejector I0?.

The alloy may be made up and melted at ground level and then elevated to the top of the stack or shot tower, e. g., by hoisting and tilting, or by pumping, or by a gas-lift (in which hydrocarbon gas may be used and ignited at the discharge to maintain the alloy in molten condition).

The vessel I I0 is provided with a vertically inclined continuous chain-type converter I |5,having one or more perforated blades |20 attached to the traveling chain in such a manner as to drag the alloy upward along the lower inclined surface housing, and permit fluid to drain back into the compartment |09. By this means, or other equivalent elevating means, substantially huid-free coarsely divided alloy may be discharged continuously from the spout at the upper end of the conveyor into the conical hopper I GI. rThis conical feed hopper is closed at the top by the removable cover 2, communicates at its lower end with the constant volume feed mechanism 3, which in turn communicates with the throat portion of the downwardly inclined injector (Venturi) feed tube 4.. This feed tub-e is arranged to discharge substantially tangentially into the lower curved portion of the chamber 5. t is desirable to arrange the feed tube to saturate the solid reactant with liquid reactant or propellant under elevated pressure and to abruptly reduce the pressure on the saturated solid reactant when it is discharged from the injector.

It is desirable to use an injector provided with a high-velocity nozzle for introducing fluid at elevated pressure into the plenum chamber Wherein a negative or reduced pressure is employed, an inlet port for feeding coarsely divided alloy into the plenum chamber, a convergent nozzle or throat portion joining the plenum chamber to a saturating tube portion, which tube leads into an abrupt expansion tube portion. The outlet end of the expansion tube portion may be provided with an axial-flow type valve closure provided with suitable stuffing box and adjusting means such as screw threads for regulating its distance from the tube. It is preferred to maintain a vacuum of about 10" Hg in the plenum chamber. However, this may be varied depending on the material handled. If ethyl chloride vapor is introduced into such an injector at a pressure of pounds per square inch gauge, any pressure within the range of 0 up to 50 pounds per square inch gauge (at which point there is a sharp change to back-flow) may be maintained in the saturating tube portion. This saturating tube portion may be constructed so that its cross-sectional area is uniform throughout its length, or it may be varied, e. g., slightly divergent toward the exit end; however, the cross-sectional area at any point thereof should not exceed the largest crosssectional area of the throat portion. The throat portion is preferably constructed with a 30 taper.

By this means, the reaction mixture may be abruptly shocked and passed directly into the circular path reaction chamber, thus facilitating rapid chemical reaction.

The chamber 5 is provided with a plurality of substantially tangentially disposed high velocity fluid jets 1, which are in communication with the fluid reactant supply tank I4 through pump I6, heater Il, and chamber I8. Tank I4 is equipped with a feed line I5.

An exhaust line 8 -communicates with the chamber 5 at the inner periphery and near the point where the upper semi-circular member 5A joints with the vertical descending member 5D, thereof. The other end of the exhaust pipe 8 communicates substantially tangentially with the side of the low Velocity cyclone separator 9. This separator is provided with an annular arrangement of downwardly ydirected spray nozzles I0, positioned above the point of communication of the exhaust line 8. The top of the cyclone separator is equipped with -a partial condenser I2, and also communicates serially with the final condenser I3, which nal condenser communicates with the fluid reactant feed tank I4.

The lower `end of the cyclone separator 9 communicates with a closed chamber II which is equipped with a strainer I9. The closed container II may provide the additional reaction period for the reactants when it is desired as mentioned above. The strainer` I9 communicates with the stripping column 20 (which may be or" the multiple tray, or packed tower type). The column 20 communicates at its lower end with the reboiler 2|. The reboiler 2| is equipped with a product removal seal pipe 22.

The chamber I| communicates with an upwardly inclined helical ribbon-type 'conveyol` 25, which conveyor in turn communicates with a storage vessel 25. The conveyor 25 is equipped with an annular heating jacket 21 at the upper end thereof. Conveyor 25 also communicates with a `vapor line 28, at a point below the heating jacket 21, and it also communicates with a backwash line 39, at a point below the vapor line 28.

A solvent supply tank 24, which is equipped with a feed inlet (not shown), communicates through pump 29 with line 30. Line 30 also communicates with the annular spray nozzles I through line 3|. Tank 24 also communicates with the upper partnof the strip-ping column 20 through line 32. The upper part of stripping column 2li communicates with condenser 23 through line 28, and this condenser in. turn communicates with tank 24.

Figure 2 schematically illustrates the process. A solid reactant is prepared in shot or the like coarsely divided form and is brought together with fluid reactant in the reactor, under reacti-on temperature and pressure conditions, with high speed fluid propulsion agitation. Reaction, attrition of solid particles and classification of solid particles occur in the reactor. As the solid reactant is reduced in particle size through reaction and attrition, the reaction products and unconsumed reactants are passed from the reactor to a separator wherein additional reaction is provided, if desired, and the desired product is separated. In addition, unconsumed fluid reactant may be separately recovered, and unconsumed solid reactant collected as or in a residue.

Figure 3 illustrates an alternative type :of reaction chamber. A substantially cylindrical chamber 43 communicates with solid reactant feed hopper 40 (which is equipped with a cover, not shown) through the Venturi feed line 4|. The Venturi line also communicates with fluid line 42. Fluid jets 44 communicate with chamber 43 at the outer circumference thereof, and are directed tangentially to a circle of somewhat smaller radius than the outer radius of the chamber The jets 44 and line 42 communicate with uid jet lines 45 and 46. The central portion of chamber y43 communicates with chamber 48 and line 50. Chamber 43 is provided with a flange 41 which protrudes above the lower surface of chamber 43. Line 50 is of smaller diameter than chamber 48, and the lower end of line 50 is set -somewhat below the iiange 41. Line `50 may be connected with a series of condensers at the upper end thereof, 5|. Chamber 48 may be connected with -chamber of Figure 1 through throat 49.

In the apparatus of Figure 4, a vessel (like vessel |535 of Figure l) is provided with a vertically arranged shaft |21 (supported by suitable bearings) carrying a horizontal disc |25, which disc is positioned slightly below the level of a body of the cooling fluid |26, and also with agitator blades |28 set in the body of cooling uid. The shaft, disc and agitator are rapidly rotated (by suitable means), and the iiuid level builds up slightly above the outer edge of the disc, the upper surface of the disc remaining relatively dry. Preferably the upper surface of the disc is in a yraised conical form. Molten alloy is passed from the spout |24 at a uniform rate onto the inner portion or `area of the rapidly spinning dis-c, and is thrown from the edge of the disc in the form of a shower or spray which is quickly quenched and solidified upon entering the body of cooling fluid. If the upper surface of the disc is in the preferred raised conical form, it will impart a downward thrust to the alloy droplets as they leave the disc. The agitator |28 serves to main- 61' tain the coarsely divided alloy in suspension in the uid and also to break up any filaments or rod-like pieces of the alloy.

Figure 5 illustrates a convenient molten alloy preparing apparatus, containing a rotating barrel member |29 provided with suitable rotating means and set in a housing member |30 provided with heating means (not shown). The rotating barrel member is provided with spiral vanelikel members |3| which facilitate the movement of incompletely molten alloy material toward the spout end thereof. The cover |32 (rotatably or xedly attached to hinged supporting member |33) may be opened and pieces of lead and sodium introduced to charge the apparatus. The apparatus is provided with means for adjusting the angle of tilt, and thus regulate the flow of alloy from the spout. The member |33 may be arranged to tilt or open upward, or horizontally if desired.

Other types of curved path reaction chambers in which turbulent flow or agitation and classification may occur are suitable. The cross section need not be tubular or cylindrical. Spiral, helical, reversed curve, annular, multistage, and the like shaped reaction vessels may be employed. Combinations of tubular and vortex type chambers may be used.

If desired, fluid propulsion jets may be positioned at the outer part or nearer the inner part of the reaction chamber '(cross section) so as to increase, decrease or otherwise modify turbulent ow in the chamber, e. g., to favor or modify double inverse helical flow, spiral flow, transverse eddy currents, or the like therein.

In one embodiment, the process of the invention may be applied to the manufacture of tetraethyl lead by the reaction of lead-sodium alloy and ethyl chloride. 'Ietraethyl lead is of great commercial importance and it is consumed in large quantities as an ingredient in gasoline and the like internal combustionengine fuels.

Various methods have been proposed heretofore for the manufacture of tetraethyl lead, e. g., from lead-sodium alloy and ethyl chloride. One type involves charging a batch of the (about lead-10% sodium) alloy into a reaction vessel and treating this with a batch or a continuous or intermittent stream of ethyl chloride. The reaction vessel may be in the form of an autoclave equipped with a rotary stirrer, or a rotating ball-mill, or similar batch type apparatus. These prior processes are subject to many drawbacks. They involve long reaction periods and leave much to be desired as to yields. The alloy particles and the sodium chloride by-products of the reaction tend to agglomerate into larger lumps, and thus a substantial amount of the alloy is shielded from contact with the ethyl chloride reactants. In addition, the agglomerated mass retains a substantial amount of the tetraethyl lead product, and the recovery of the product therefrom is tedious and wasteful.

There is considerable hazard involved in large reaction batch operations containing a large charge of the alloy. The reaction may occur with explosive violence. If moisture should happen to come in contact with the alloy, an explosion may occur. Where the process is conducted under pressure, there is considerable health hazard from any of the highly toxic tetraethyl lead vapors which might escape from'the various valves, stuing boxes and mechanical closures involved in batch type reaction vessels.

In accordance with the invention, it has been foundfthat theY above drawbacks may be overcome and the tetraethyl lead produced in a commercially more advantageous manner.

For the preparation of tetraethyl lead, using the apparatus illustrated in Figure 1, lead metal and sodium metal may be introduced and molten in vessel II. The molten alloy may be passed through the perforated member |02, to form droplets which are substantially solidified by passing through substantially inert gases and then quickly chilled or cooled by passing into kerosene or the likev light petroleum oil cooling huid in' vessel |05, to give very brittle particles in the form of shot having a protective film coating; which particles are especially reactive when processed in the reaction chamber as discussed below. The shot is continuously tran.,- ferred to compartment |09 of vessel I lil and then to the hopper IUI. 'I'he fluid supply tank Ill is lled with ethyl chloride. thyl chloride is maintained in the chamber I8 at a pressure of about 100 pounds per square inch gauge and a temperature of about 180 F. The alloy is fed into the reaction chamber 5 by means of the feeder mechanism 3 and the injector 4 (including the ethyl chloride jet from line S). Ethyl chloride is also injected through jets l.

Both the amount of the ethyl chloride and that of the lead used are in excess of the stoichiometric requirements. Preferably, the amount of C ethyl chloride is chosen so as to impart an average linear velocity of about 10 to 100 feet per second within the reaction chamber, i. e., turbulent ow with transverse eddy currents. This causes vigorous agitation therein, and associethyl chloride and the alloy occurs rapidly at lent fiow movement imparted to the particles of 1 the fluid propellant which is tangentially introluced from the outer periphery of this region insures that the reacting surface is maintained in most reactive form by removal of any shielding coating and by the attrition of the alloy particles associated with the high energy collisions in the reaction chamber and chemical erosion. The by-product sodium chloride does not lump up or occlude unreacted alloy or finished reaction product, and it is maintained in a nely divided state. The alloy particles may travel around the reaction chamber one or more times in being reduced to a substantially finely divided form.

The reaction mixture of unconsumed reactants, reaction products and residue travels near the inner periphery of the chamber 5, and is withdrawn through exhaust line 8. This withdrawn portion is then processed to recover tetraethyl lead, unconsumed ethyl chloride, and a residue which may contain recoverable lead. In

. tained without giving unduly high pressures.

one embodiment, the withdrawn reaction mixture is passed to the low pressure cyclone separator 9 and sprayed with acetone (from tank 24 through the spray nozzles I0). The ethyl chloride vapor undergoes a scrubbing due to the effect of the partial condenser I2, and then passes upward to the condenser I3, where it is condensed and returned to the ethyl chloride tank I4. Additional make-up ethyl chloride may be introduced through line I5, if necessary.

The acetone solution of tetraethyl lead plus the solid residue passes to chamber I I. The acetone solution, removed therefrom through strainer I9, passes to the stripping column 20. The acetone is vapor-ized, and the vapor passes to condenser 23, is condensed, and then passes to acetone solvent. tank 24. Finished tetraethyl lead is removed through line 22.

The solid residue passes from chamber I I to the conveyor 25 wherein it is back-washed with acetone, supplied through line 30. It is then heated at a temperature of about 200 F. to expel acetone vapors and impart a final drying effect to the spent alloy. The acetone vapor passes up to the condenser 23, is liquied, and then passes to tank 24. rlhe spent alloy passes to chamber 26. It may be removed and processed to recover any lead therein, in accordance with known procedures.

The reaction chamber 5 may be supplied with a temperature regulating jacket, or set in a temperature regulating bath, in order to regulate the temperature thereof. Where the ethyl chloride is present as a vapor in the reaction chamber, the expansion of the ethyl chloride leaving the jets is accompanied by a refrigerating effect. This may be adjusted so as to control the temperature of the reaction system, i. e., absorb the heat evolved by the exothermic chemical reaction in the formation of the tetraethyl lead.

The acetone spray in the separator serves to strip tetraethyl lead from the vapors as well as to help settle the spent alloy particles and byproduct, sodium chloride. The effect of the partial condenser I 2 is to further strip tetraethyl lead from the vapors of ethyl chloride.

It has been found that the recovered and recirculated ethyl chloride tends to give a higher yield of tetraethyl lead, than does fresh ethyl chloride. It is thought that some material carried over in the recovered ethyl4 chloride has a beneficial effect on the reaction.

rl'he process may be carried out in apparatus which includes heat exchange devices; e. g., to use the heat contained in the ethyl chloride vapor to preheat fresh ethyl chloride liquid.

The reactant in fluid form may contain a diluent or solvent and should be readily owable in order that sufficient propulsion may be ob- If the reactant is in the form of a liquid, it is preferable that the viscosity thereof should not be higher than that of an about S. A. E. 50 motor lubricating oil at ordinary room temperatures.

The reaction may be conducted with the iluid reactant in either the vapor phase or the liquid phase.

In an illustrative vapor phase operation, a Figure 1 type of apparatus is used with a reaction chamber of 1.45 sq. inch inner cross-sectional area, the top and bottom turns of a radius of curvature of 6 inches, and the vertical connectors 26 inches in length; the saturating tube portion of the injector is of the same inner crosssectional area as the reaction chamber, and ve 'acreage trogen may be employed vas the fluid propulsion agent. In this case, the amount of the organic halide would be about sufcient to complete the chemical reaction. The fluid reactant could be introduced in one set of one or more jets; and the fluid propulsion agent, e. g., nitrogen in another set of one or more jets.

,If desired, the above-described product separation and recovery system may be replaced by Vapor Phase Liquid Phase Duration of Run 1 hour 30 minutes. Weight of Alloy Charg 145 lbs 24 lbs. v Composition of Alloy-- Na, 90% Pb 10% Na, 90% Pb. Reactor Temperature. 135 F 125 F.

Pressure at Reactor Inlets Pressure at Reactor Outlet Total Ethyl Chloride Charged Rat Chloride Feed Tetraethyl Lead Produced Yield Based on Sodium Consumed Ethyl Chloride Consumed Yield Eiiiciency Based on Ethyl Chloride. Average Size of Alloy Feed Average Size of Lead Residue. Velocity at Reactor Outlet 10 mesh.

microns.

10 F. P. S.

l Pounds per square inch guage. 2 Feet per second average linear mass velocity.

Iihere is also a tendency for a caking or coating of the balls (to form lumps) in the mill, and this will similarly isolate the two reactants from each other and occlude the reaction product so as to make recovery thereof difficult.

In the normal operation of the above-described process, there will be no appreciable health hazards from the escape of tetraethyl lead vapors. The high pressure part of the reaction system, wherein tetraethyl lead occurs, is completely closed. If desired, the pumping units may be completely submerged Within the corresponding tanks, in order to avoid possible leakage of liquid from any stuffing boxes or rotary shaft seals. If desired, the condensing units and tanks may be set at a suitable height relative to the remainder of the apparatus, so that the static pressure of the liquid will be sufficient for movement of the liquid without the use of pumps.

Other proportions of lead to alkali may be used in the alloy, e. g., containing mor-e than about 12.5% sodium. The alloy may be made up from one or more alkali metals, e. g., mixtures of alkali metals may be used. Other organic halides may be used, e. g., ethyl bromide, and other solvents than acetone may be used; as the art will readily appreciate in view of the above descriptions. A higher boiling fraction of gasoline may be used as a solvent; and the solvent solution of the tetraethyl lead could be directly blended with gasoline to give a desired motor fuel.

If desired, known promoters or catalysts may7 be included in the reaction mixture. Ferrie chloride or anhydrous aluminum chloridemay be suspended in an inert vehicle, such as a petroleum distillate, and introduced in controlled amounts into the reaction chamber at a convenient point.

If desired, the ethyl chloride vaporizing and condensing apparatus may be replaced by a mechanical apparatus for developing the required pressure. Alternatively, an inert gas such as niconventional quenching and steam distillation methods. For instance, the mixture of tetraethyl lead and spent alloy can be discharged from the lower end of the cyclone separator 9 into a chamber containing a plurality of steam jets and then 'to a second cyclone separator, wherein the spent alloy particles are separated by a gravity effect, while the steam and tetraethyl lead vapor are removed/condensed, and the two immiscible liquids separately removed from the condensate. l

f- Where the alternative reaction chamber of Figure 3 is employed, it is preferred that the fluid reactant be present in the form of a vapor, with or vwithout additional or diluent gas.

In View of the foregoing disclosures, the art will appreciate that other methods may be used to solidify molten reactant in coarsely divided solid form and contact it with the reactant in fluid form so as to achieve the benefits of high speed fluid propulsion, while the reaction is in progress, together with maintaining the solid reactant in active contact with the fluid reactant; e. g., by a shearing or cleaning action to remove any shielding coating, or by an attrition of the solid particles to present clean solid reactant surface; and classifying or separating substantially finely divided material from the reaction zone. In View of the foregoing disclosures,` variations and modifications of applications of the invention will be apparent to those skilled in the art; and the invention contemplates all such other methods, variations and modications except as do' not come within the appended claims.

This application is a continuation-in-part of my copending application Serial No. 28,614 filed May 22, 1948.

Iolaim:

1. A process for the preparation of alkylated lead which comprises forming molten lead alkali metal alloy into substantially solidified coarsely divided hot particles in substantially round form and quickly cooling said particles in light petroleum oil whereby a protective lm coating is formed on said particles and the metal therein is Very brittle, mixing said coated particles with alkyl chloride to give a mixture which tends to provide a shielding coating on said solid interferring with the eiiicient reactive contact of the alkyl chloride with the alloy, mixing these reactants under high spe-ed agitation induced by fluid propulsion while the movement of said mixture is confined to a substantially closed curved path, under reaction temperature and pressure conditions, whereby the chemical reaction is intensified and fresh reactant surfaces are maintained, and separately recovering reaction products from the process.

2. A process of claim 1 wherein the solid particles suspended in the light petroleum oil are substantially separated from the oil and then mixed with the iiuid reactant and the path of movement of the reactant mixture is a substantially elliptical path and the reactants are subject to greatest centrifugal compression substantially at one end of said substantially elliptical path of movement and the duid propellant is introduced tangentially from the outer periphery of this substantially elliptical path region of greatest compression.

3. A process of claim 2 which is carried out in a continuous manner and wherein the suspension of solid particles in the light petroleum oil is flowed to the zone of separation of the solid therefrom, the alloy is in the form of about 4 mesh substantially spherical particles and the elliptical path is substantially vertical with the region of greatest compression at the lower end thereof.

4. The process of claim 3 wherein the reaction mixture contains a catalyst and the alkyl chloride reactant is in the form of a liquid.

5. A process of claim 4 wherein the alkyl chloride is ethyl chloride.

6. A process of claim 5 wherein the Vhigh speed agitation isinduced by inert gas propulsion.

7. A process of claim 5 wherein the removed more nely divided portion of the reaction mixture is contacted with a solvent for tetraethyl lead, and a solution of tetraethyl lead in said solvent is separated from unreacted ethyl chloride and from the residue.

8. A process of claim 3 wherein the alkyl chloride reactant is in the form of a vapor.

9. A process `of claim 8 wherein the alkyl chloride is Yethyl chloride.

10. A process of claim 9 wherein the removed more nely divided portion of the reaction mixture is contacted with a solvent for tetraethyl lead, and a solution of tetraethyl lead in said solvent is separated from unreacted ethyl chloride and from the residue.

11. A process of claim 9 wherein the reaction mixture contains a catalyst and the high speed agitation is induced by inert gas propulsion.

12. A process of claim 11 wherein the reactant mixture moves with an average linear velocity in the range of 10 to 100 feet per second.

13. A process of claim 12 wherein the solid revactant in coarsely divided form is mixed with the fluid reactant under elevated pressure and then the pressure is reduced abruptly and then the reactants are mixed under the high speed agitation.

ROBERT STANTON'.

REFERENCES CITED 'llrc following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,148,194 Seifert et al July 27, 1915 1,962,173 Calcott et al June 12, 1934 1,974,167 Voorhees Sept. 18, 1934 2,029,301 Bake Feb. 4, 1936 2,043,224 Amick et al June 9, 1936 2,109,005 Bake Feb. 22, 1938 2,310,806 Nourse Feb. 9, 1943 2,351,091 Bar June 13, 1944 2,391,723 Mann Dec. 25, 1945

Claims (1)

1. A PROCESS FOR THE PREPARATION OF ALKYLATED LEAD WHICH COMPRISES FORMING MOLTEN LEAD ALKALI METAL ALLOY INTO SUBSTANTIALLY SOLIDIFIED COARSELY DIVIDED HOT PARTICLES IN SUBSTANTIALLY ROUND FORM AND QUICKLY COOLING SAID PARTICLES IN LIGHT PETROLEUM OIL WHEREBY A PROTECTIVE FILM COATING IS FORMED ON SAID PARTICLES AND THE METAL THEREIN IS VERY BRITTLE, MIXING SAID COATED PARTICLES WITH ALKYL CHLORIDE TO GIVE A MIXTURE WHICH TENDS TO PROVIDE A SHIELDING COATING ON SAID SOLID INTERFERRING WITH THE EFFICIENT REACTIVE CONTACT OF THE ALKYL CHLORIDE WITH THE ALLOY, MIXING THESE REACTANTS UNDER HIGH SPEED AGITATION INDUCED BY FLUID PROPULSION WHILE THE MOVEMENT OF SAID MIXTURE IS CONFINED TO A SUBSTANTIALLY CLOSED CURVED

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