US1113178A - Process of producing barium and strontium oxids. - Google Patents

Description

' tity being readily determined by simple- UNITED STATES PATENT oFFioE.

- HARRY e; axnns, or TORONTO, ONTARIO, CANADA.

PROCESS No Drawing.

, Specification of Letters Patent.

or PRODUCING BABIUM AND s'rnon'rium OXIDS. I

To all whom it may concern:

Be it known that I, HARRY- G. AKERs,a citizen of Canada, and subject of the King of Great Britain, residing at Toronto, in the Province of Ontario and Dominion of Canada, have invented certain new and use ful Improvements in Processes of Producing Barium and Strontium Oxids; and I do hereby declare 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 and use the same.

This invention relates to the production of barium and strontium oxids from their carbonates, and has for its purpose to provide a process which will accomplish these objects in peditious than those heretofore proposed.

With these and other objects in view the invention consists in the novel steps and combinations of steps constituting'my process, all as are more fully hereinafter disclosed and partic larly pointed out in the claims.

As is well known, barium or strontium carbonates which have been employed in the refining of molasses and therefore are more or less contaminated with lime, silica, organic substances, etc., are difiicult to fuse, and do not even (1., the exact temperature depending upon the amount and character of the impurities present. I have discovered, however, that these impure'carbonates can be readily melted at approximately 1200 C. by adding small quantities of fluxes, such as fluorspar, soda ash, bor'ax, etc, the best quanand Well known tests, and depending upon the character and quantity of the impur ities in the carbonates. I have further dis covered that after the said carbonates, whether pure or not, have been melted they may be readily changed into oxids almost to completion at temperatures approximating to 1200 C. provided the partial pressure of the carbon dioxid liberated by the reaction be kept below that of the atmosphere and suflicient carbon be present. In some cases I have found a carbon lining for portions of the furnace 'to yield good results, as it tends to assist in changing the carbonates nto oxlds, and it is comparatlvely inexpensive to renew.

In carrying out my process the barium' a manner more efficient and ex- 1 melt at 1200 C. or 1300? or strontium carbonates according to the nature of the impurities present may be.

w ith or without an admixed reducing agent, depending upon the subsequent treatment said carbonates are to receiveffed into a suitable furnace such, rotary cement kill with a flux may be conveniently in the form of a sludge, in which form it usually comes from the carbonat-ing tanks, and canbe dried in the stack end of the furnace by means of the exit-gases. This charge may then be melted in the body of the furnace and admixed with a reducing agent as it is fed along, if no such agent be already presout, and finally delivered into a suitable receptacle in a molten condition.

By so pro-portioning the carbon or other reducing agent as to compel a large proportion of the carbon monoxid instead of carbon dioxid to be given off, the exit gases will consist largely of nitrogen and carbon monoxid, CO mixed with a less quantity of carbon dioxid, C0,, the partialpressure of the latter will be low and the full value of said gases may be employed to assist the heating and reduction of the charge. In other Words, adding a flux to these carbonates to allow them tofuse at approximately 1200 C. and mixing them with a carbonaceous substance, I accomplish the most desirable results of attaining a lower melting point for said carbonates, whichallovs 's a better contact between the c'arbonate and the reduc- I Patented Oct. 13;, 1914. Application filed May 8, 1913. Serial No. 766,410.

by the simple expedients of mg agent] and consequently allows the reduction to proceed readily at comparatively low temperatures. Further, the lowering of the said partial pressure greatly facilitates the reduction of the carbonates and enables me to accomplish the reduction to almost completion at temperatures approximating 1200 C. as above stated, a result which would not be possible by the old methods, while at the-same time the larger quantity of carbon'monoxid produced, enables me to get a higher fuel value from the exit gases to aid in the reduction.

While the charge is in its molten condition it is sometimes desirable to further refine it by introducing a-reducing agent by means of a nozzle delivering compressed air vcharged with said agent in a, finely divided condition, or said agent may be blown through the molten material. These latter expedients'will be also useful when the I admixed therewith in an reducing agent has not been initially mixed with the charge as above referred to or was insufficient quantity,'o r has been burnt out by the gases produced in the previous stages of the process.

The advantages of my process will be aparent when one considers the economy due a to the/drying and'preheating of the crude carbonates which are usually 1n the form of a sludge, the continuity'of the process, the cheapness of the equipment necessary for carrying it out, the lower temperature and less .heat required, for the separation, and

andtherefore I donot wish to be limited to the above disclosure, except as may be required by the claims.

What I claim is p '1. The continuous process of roducing barium or strontium' oxids from t eir crude carbonates which consists in mixing the carbonate with a flux to lower its melting point; adding a reducing agent to the charge; meltingthe vcharge at a temperature of approximately 1200 .C.; igniting the evolved gases to heat the charge and topreheat the incoming charge; and maintainlng a reducing atmosphere in the reacting vessel conscribed.

2. The continuous process of producing taming said charge, substantially as debarium or strontium oxids from their crude carbonates which consists in mixing the carbonates with a flux to lower the melting point; adding a reducing agent to the charge; melting the charge at a temperature of approximately 1200 C.; igniting the evolved gases to heat the charge and to preheat the incoming-charge; maintaining a reducing atmosphere in the reacting vessel containing said charge; and causing the gases produced by the combustion of the fuel employed'in heating the furnace to dilute and thereby lower the partial pressure of any evolved carbon dioxid'from said charge, substantially as described.

3,. The continuous process of producing barium or strontium oxids from their crude carbonates which consists in mixing the carbonates with a flux to'lower the melting point; adding a reducing agent to the charge; melting the charge at a temperature of approximately 1200 0.; refining the mass-by again adding afedu cing agent; causing the gases produced by the combustion of the fuel employed in heating the furnace to dilute any liberated carbon dioxid and thereby reduce its partial pressure; igniting-the evolved gases to heat the charge and to preheat the .incoming charge; and maintaining a reducing atmosphere in the reacting vessel containing said charge, sub- 'stantially as described.

i 4. The continuous process of producing barium or strontium oxids from their crude carbonates in the form of a sludge which consists in mixing the carbonates with a flux to lower the melting point; adding a reducing agent to the charge; melting the charge at, a temperature of a proximately 1290 C. 1n a carbon lined fiirnace; igniting the evolved gases to heat the charge and to preheat the incoming charge; maintaining a reducing atmosphere in the reacting vessel containing sald charge; and causing the gases produced by the combustion of the uel employed in heating the furnace to dilute and thereby lower the partial pressure of an evolved carbon dioXid from said charge, su "stantially as described.

In testimony whereof I aflix my signature, in presence of two 'witnesses.

HARRY GQAKERS. l/Vitnesses:

G. O. KINGSTON, J. JORDAN.