US481007A - Art of making white lead - Google Patents

Description

-($pecimens.)

G. D.. COLEMAN. ART OF MAKING WHITE LEAD.

No. 481,007. Patented Aug. 16, 1892.

J Tit 13 2 2 1/54 Jl METAL LEVEL.

ATTEST: 1 16.5. INVENTOR:

8 12, Geo. D.CoZeman, 5y

. u flzorne y.

N'rsn STATES GEORGE D. COLEMAN, OF CHICAGO, ILLINOIS.

ART OF MAKING WHITE LEAD.

SPECIFICATION forming part of Letters Patent No. 481,007, dated August 16, 1892.

Application filed August 12, 1890. Renewed May 23, 1892. Serial No. 434,105. (Specimena) To all whom it may concern:

Be it known that I, GEORGE D. COLEMAN, a citizen of the United States, residing at Chicago, 1n the county of Cook and State of Illinois, have invented a certain new and useful Improvement in the Art of Corroding Lead; and I do hereby declare the following to be a full, clear, and exact description of the same, such as will enable those skilled in the art to which the invention appertains to use and carry on the same.

The present invention relates to the treatment of metallic lead in a divided or comminuted state so as to corrode the same and produce at will either of the following lead products or compounds, viz: lead suboxide, lead protoxide, or lead hydrocarbonate, commonly called white lead, or mixtures of either of the same.

The present invention has as its basis the recognition and application of the primary and fundamental fact that the chemical reactions in the interior of the apparatus are greatly dependent upon and sensitive as well as responsive to even comparatively moderate physical changes of pressure and temperature. By the proper regulation and control of such physical agencies I am enabled in my present process to hasten or retard chemical action to such a degree that lead suboxide, lead protoxide, or lead hydrocarbonate can be pro duced at will as distinct and separate articles of manufacture. A want of recognition and an absence of control and regulation of such physical agencies in what may be termed the tumbling process of producing white lead have heretofore rendered all such prior attempts to manufacture white lead unsuccessful, based as they were upon the misconception that chemical forces alone needed attention and were to be depended upon alone to bring the growth and development of this tumbling process to a practical success.

My present improvement therefore embraces a process of treating comminuted metallic lead in which the temperature and pressure are under complete control and regulation so as to enable the production at will of either lead suboxide, lead protoxide, or lead In carrying out my present improved process or art of corroding lead I make use of a closed corroding-vessel arranged to rotate and preferably constructed and arranged in the manner illustrated in the accompanying drawings, in which- Figure l is a general elevation, partly in section, of a form of apparatus adapted for use in carrying out my present process; Figs. 2 and 3, detail longitudinal or axial sections of the revolving cylinder and the connections thereto; Fig. 4, a detail elevation of the axially-arranged pipes through which the water and gases pass to the interior of the cylinder, and Fig. 5 a cross-section of the same at line 00 00.

Similar numerals of reference indicate like parts in the several views.

In the construction shown in the aforesaid drawings the cylinder or cask 1 for containing the comminuted lead, water, and gases is mounted in bearings on a suitable frame or base so as to rotate, motion being communicated to the cylinder by any suitable means, preferably by tight and loose pulleys 2 and 3 upon a pinion-shaft that drives the spur-gear 4, keyed or otherwise secured to the hub or axle of the cylinder 1, the metal-level and the water-level being indicated by dotted lines in said figure, the water-level being a little below the axis of the cylinder and above the inner downwardly-projecting end or neck of the siphon or outlet-pipe 5.

The finely-divided metallic lead is introduced into the cylinder through a hand-hole in any suitable manner, but preferably in a substantially continuous manner automatically, and enough. water isintroduced to fully cover the lead, preferably in bulk three or four times the amount of lead, the water-level being in any case below the axis of the cylinder.

ater is supplied to the cylinder 1 from an elevated closed tank 6 by a valved pipe 7, that connects with the axially-arranged pipe 8, arranged in the cylinder, which is of same diameter and slotted longitudinally, as shown, so as to discharge water in a very uniform manner.

The supply of carbonic-acid gas and air is received under pressure from any suitable source through the pipes 9 and 10, that join ICO together in a eommingling-pipe 11, that discharges into the interior of the cylinder through the longitndinally-extending perforated pipe 12, arranged concentrically within the slotted water-pipe 8, as clearly indicated in Figs. 2, 3, 4:, and 5. The outlet from the cylinder is through the siphon or dischargepipe 5, passing through the hollow axis of the cylinder and discharging into the tub or filter 13. Packing- glands 14, 15, and 16 are provided on the axial parts to maintain tight joints between the pipes 12, 8, and 5 and the hollow axis of the cylinder, as clearly illus trated in Figs. 2 and 3.

In the construction illustrated, l7 represents a pressure-gage connected to the inletpipe for the gases to indicate the pressure of the same, and 18 a similar gage for indicating the pressure of water in the tank 6.

19 is a suitably-constructed pump having its supply connected to the filter of tub 13 and its discharge connected to the elevated closed tank 6 by a pipe 20, the purpose being to cause a continuous circulation of the water from the tank 6 through the corroding-cylinderl to the filter 13, and from thence by means of the pump 19 returned back to the tank 6.

The apparatus herein described is substantially the same as that set forth and claimed in my application for Letters Patent for improvement in apparatus for corroding lead filed August 17, 1891, Serial No. 402,921, and I make no claim in the present application to features of construction embodied in the aforesaid application, Serial No. $02,921.

In carrying my improved process into effect the following general directions may be ob served: Charge the corroding-cylinder (usually of a size four feet in diameter and five feet long) with a proper quantity of granulated lead and sufficient water to reach an indicated water-level below the axis of the cylinder and air, either alone or combined with carbonic-acid gasinabout equal vol um es, to fill the space above the water. Then impart rotary movement to the cylinder, usually forty to sixty-five revolutions per minute, un' til the resultant product is of a bluish tint. Preserveacontinuonsinfiowingandontflowing stream of water through the cylinder in order to attain the following results: The control and regulation of the temperature in the cylin der by increasing or decreasing the volume, temperature, or flow of the water and the washing out and removal of the products of corrosion from the cylinder, so as to keep the lead bright and clean and in the best possible condition for oxidation, attrition, and carbonation in a contin nous manner and at the same time afford a continuous sample of the product for inspection at the point of discharge from the water-eduction pipe, the gas-supply under pressure being maintained intact by any usual means.

From practical experiment I find the following degrees of temperature and pressure best adapted to the rapid formation of the different desired products of the present corroding process, to wit: lead suboxide, lead protoxide, and lead hydrocarbonate or a mixture of the same.

Formula 1.For the production of lead suboxide, a temperature of 150 to 210 Fahrenheit and under the ordinary atmospheric pressure.

Formula 2.For the production of lead bydrocarbonate or white lead, a temperature of to 150 Fahrenheit and a pressure of thirty pounds.

FormaZa 3.For the production of lead protoxide, a temperature of 75 to 150 Fahrenheit and a pressure of fifteen pounds.

Formula 4.For the production of a mixture of lead suboxide, lead protoxide, and lead hydrocarbonate, a temperature of 32 to 75 Fahrenheit and a pressure of fifteen pounds.

If the purpose is to produce lead suboxide, formula 1 will be followed until the charge is oxidized and converted into substantially pure lead suboxide, as indicated by its blueblack color. In following this formula the presence of air alone is required, and the supply of carbonic-acid gas will in consequence be cut off.

\Vhite lead can be made directly by following formula 2 and rotating the corrodingcylinder, according to the general instructions therefor, until its contents are oxidized and carbonated and have a blue tint and consist of white lead colored by a little lead suboxide, which can be subsequently treated in any suitable manner with air and carbonic acid to be converted to a uniform standard of color, the.

Lead protoxide can be made by following formula 3 and rotating the cylinder according to the general directions or until its contents are oxidized and consist of substantiallypure lead protoxide, as indicated by the yellow color and the proper tests.

hite lead can also be made by following formula 4 and rotating the cylinder and otherwise proceeding as in formula 2.

Formula 1 is the best for making lead suboxide, the high temperature causing rapid oxidation, and at the same time a strictly pure lead suboxide is formed under new physical and chemical conditions that give it an unequaled facility of oxidation and carbonation.

The effect and importance of pressure in raising the decomposing temperature of white lead is shown in formulas 1 and 2, where it is raised from 75 Fahrenheit in formula 1 to 150 Fahrenheit in formula 2 by increasing the pressure from fifteen pounds in formula 1 to thirty pounds in formula 2. By such means it becomes practicable to use those temperatures and pressures that are the most simple and effective in operation and at the same time the most rapid and desirable in the products and other results obtained therefrom. In fact, it thus becomes a possible and simple matter to calculate in advance a pressure and temperature combination or formula suited to the use of any particular pressure or temperature that may be desired for any special use or purpose. In view, therefore, of the great number of such rules or combinations that would have a practical and important application for the purposes herein specified, I do not confine my present invention to any one precise or particular formula heretofore given, and may modify and change the same as particular circumstances and the judgment of the operator may suggest without departing from the spirit of my present invention.

Having thus fully described my said invention, what I claim as new, and desire to secure by Letters Patent, is

1. The herein-described improvement in the art of corroding lead in the presence of water and a suitable corroding-gas, the same consisting in preserving the surface of the lead particles in a clean condition best adapted for corrosive action by a flow of water that acts to remove the corroded lead as fast as formed, substantially as herein described.

2. The herein-described improvement in the art of corroding lead in the presence of water and a suitable corroding-gas, the same consisting in conducting the corroding process under definite and controllable degrees of pressure and temperature and at the same time preserving the surfaces of the lead particles in a clean condition best adapted for corrosive action by a flow of Water that acts to remove the corroded lead as fast as formed as well as to carry off the surplus heat generated by the physical and chemical reactions in the process, substantially as herein described.

In witness whereof I hereunto subscribe my name this 9th day of August, A. D. 1890.

GEORGE D. COLEMAN. Witnesses:

GEORGE P. BARTON, ELLA EDLER.

Images