US2166659A - Process for the treatment of beryllium ores - Google Patents

Description

Patented July 18, 1939 ruoouss FOR. THE TREATMENT 0F BER- ORES Daniel Gardner, Rueil-Malmaison, France, as-

signor to Maatschappij voor Thermo-Chemie N. V., Arnheim, Netherlands, a. company of the Netherlands No Drawing. Application March '7, 1938,

Serial No. 194,378

12 Claims.

, This invention relates to processes for thesuch as iron and manganese oxides, fluorides,-

lime, etc., the best known being beryl (3Be0. Al2O3.6SiO2) In the bulk of beryllium ores the content of beryllium-oxide is rather low, the average being from 11 to 15%.

The methods hitherto known for treating beryllium ores with a view to extracting beryllium compounds therefrom and thereafter reducing said compounds to the metal are rather laborious and expensive and their yield is not always satisfactory.

The principal object of my present invention is a process such that in one single stage the beryllium in the ore is entirely oralmost entirely converted into beryllium sulphide.

Another object of my invention is an improved one-stage sulphidising process for the treatment of beryllium ores, followed by a suitable treatment of the beryllium sulphide thus formed so as to convert the same into'beryllium or beryllium alloys.

With these and. other objects in view, I suggest to first mix the suitably crushed and pulverized ore with asubstantial proportion of carbonaceous material, such as low temperature carbonisation coke or powdered coal with a low ash content, and heat this mixture in sulphur vapours and/or a gaseous or vapourized non-metallic sulphur compound such for example as carbon bisulphide or sulphuretted hydrogen, to a temperature from about 1800 0., preferably to about 2000 C., for a length of time suflicient to convert into the sulphidic form practically-the total amount of the beryllium compound originally present in the ore. This conversion of the beryllium compound into the beryllium sulphide may be carried out in an electric resistance furnace having a graphite tube the reaction being performed in the graphite tube.

Very good results have been obtained with a mixture of equal parts by weight of ore and coke or coal, but other proportions may be used without departing from the scope and the spirit of my invention.

It is pertinent here to remark that the presence of the carbonaceous material is quite essential, since in the absence thereof the amount of beryllium sulphide that can bev extracted from the reaction mass would begreatly reduced and the process would no longer be commercial.

. terial and the sulphurous vapour.

Obviously, the yield of beryllium sulphide depends upon the length of time during which the ore is subjected, at the high temperature stated, to the combined action of the carbonaceous ma- In practice it has been found that treatment during one hour is ordinarilysufficient to sulphidise practically the whole amount of beryllium in the ore.

The process is preferably carried out so as to take place in the form of a continuous operation.

The following table shows the influence of the temperature on the yield, assuming a stream of carbon bisulphide vapours being used for the sulphidising process:

The optimum temperatures range from 1950 to 2000 C. At 2000 0., about 98.5% of the beryllium oxide is converted into sulphide adapted to be extracted.

The result of my novel sulphidising process is a mass containing practically the whole amount of beryllium and. aluminium, the greater part of the silicon, and also the impurities such as iron and manganese, if any, in the form of sulphides. During the reaction, only a part of the silicon is lost through distilling, together with 'minor quantities of the aluminium and beryllium compounds.

After the solid reaction mass has been removed from the furnace and suitably pulverized, it is subjected to either a wet or to a dry treatment with a view to the production of beryllium there- .from.

In the first case, an excess of diluted hydrochloric acid (4%) or sulphuric acid is used, and the temperature is slowly raised to the boiling point, whereupon the mass thus obtained'is filtered. This filtration does not olier any particular difliculty, contrary to the filtration of other beryllium compounds. Assuming hydrochloric acid being used, the filtrate will contain the beryllium, the aluminium and the silicon, and possibly also traces of iron, manganese etc. in the form of their respective chlorides. Both the filtrate and the solid residue are analysed in order to ascertain if the full amount of the beryllium compound has been extracted from the ore. The sulphuretted hydrogen liberated during the hydrochloric acid treatment may be recycled for sulphidising a further quantity of ore.

The filtrate may be treated in the ordinary manner either with sodium carbonate and thereafter with ammonium carbonate, or with sodium hydroxide, whereby the beryllium compound is extracted and obtained in the form of beryllium oxide.

In the seconod case, the mass removed from the furnace and suitably pulverized is subjected to the action of gaseous hydrochloric acid, or of dry chlorine, whereby the sulphides are also converted into chlorides with the liberation of sulphuretted hydrogen and sulphur, respectively, and these chlorides can now readily be separated by a distilling operation owing to the fact that the boiling points of said chlorides difier sufllciently widely. In this connection it is to be noted that the boiling point of silicon tetrachloride is about 60 C., that of aluminium chloride is about C., that of ierro chloride is about 360 and that of beryllium chloride is about 520 C.

The beryllium chloride thus isolated can be converted into beryllium oxide, or, if so desired, directly into beryllium sulphide, this conversion being carried out by treatment at about 2000 C. with sulphur and suitable carbonaceous material.

The beryllium oxide obtained in either case is very pure. It is again subjected to a sulphidising process, whereby beryllium sulphide is formed. Since this sulphide has a comparatively low heat of formation (68 cal. per gram molecule), a very suitable method of eiiecting its reduction is to heat it with a metal, the heat of formation of the sulphide of which sufliciently exceeds that of beryllium sulphide. Suitable metals for this purpose are, inter alia, magnesium, barium, strontium and calcium, but especially aluminium. Thus, the beryllium sulphide may be mixed with aluminium and heated in a. reducing. or in an.

inert gaseous atmosphere and in the substantial absence of moisture, nitrogen, oxygen or oxygencontaining gases, for example, in an atmosphere of hydrogen, hydrocarbons or argon, whereby aluminium sulphide and metallic beryllium are produced. I

Alternatively, the beryllium sulphide may be heated with the metal in the presence of a flux such as beryllium fluoride, with or without the addition of the fluoride of the metal used.

As another alternative, the reduction of the beryllium sulphide may be eflected by heating it in a stream of hydrogen to a high temperature of say 1350", whereby the sulphur splits ofi and can becollected in the form of sulphuretted hydrogen, from which the sulphur can be'recovered to be recycled for the sulphidising process.

As a result of the decomposition of the beryllium sulphide, the beryllium is left in the form of metal and can be sublimed or distilled, the beryllium vapours being collected in a condenser, whereby beryllium of a high degree of purity is produced. If desired, in order to obtain beryllium alloys directly, there may also be present in the condenser a molten charge of any other metal with which the beryllium is to be alloyed.

If the reduction of the beryllium sulphide is carried out with an excess of aluminium or other suitable metal, and at a high temperature of say 1800-2000 0., the beryllium metal is directly obtained in the form of an alloy with the metal used.

It has been found that the reduction of beryllium sulphide can be greatly improved by mixing it with copper sulphide and reducing the mixture by heating it with aluminium or any other metal suitable for the purpose, or by reducing the beryllium sulphide by heating it with a mixture of aluminium and copper. In either case, the yield of beryllium metal is considerably increased.

The process outlined above for the production of beryllium from its ores is comparatively cheap, as it requires only relatively small amounts of chemicals and can be carried out in a simple installation. Moreover, it permits of about .90% of the total amount of beryllium contained in the ore to be recovered as pure metal.

What I claim is:

1. In a process for treating beryllium ore for the production of beryllium therefrom, sulphidising the ore in the presence of .a substantial pro.- portion of carbonaceous material at a' temperature ranging from about 1800 C. to about2000 C. whereby volatilization of the beryllium sulphide is substantially prevented and for a length of time sufiicient to convert the greater part oi the beryllium in the ore into beryllium sulphide,

treating the reaction mass with an excess of a diluted strong mineral acid, filtering the mass, isolating from the filtrate thus obtained the beryllium compound in the form of oxide, converting the beryllium, oxide thus isolated into beryllium I sulphide, and reducing the beryllium sulphide thus obtained to beryllium metal.

2. In a process for treating beryllium ore for the production of beryllium t herefrom,,sulphidising the ore in the presence of a substantial proportion of carbonaceous material at a temperature ranging from about 1800 C. to about 2000 C. whereby volatilization of the beryllium sulphide is substantially prevented and for a length of time suflicient to convert the greater part of the beryllium in the ore into beryllium sulphide, treating the reaction mass in a gaseous chlorinating atmosphere so as to convert the beryllium sulphide into beryllium chloride, isolating the beryllium chloride by distillation, converting-the beryllium chloride thus isolated into beryllium oxide, subjecting the beryllium oxide thus obtained to asulphidising process, and reducing the beryllium sulphide 'thus obtained to beryllium metal.

3. In a process for treating beryllium ore for the production of beryllium therefrom, sulphidising the ore in the presence of a substantial prolium in the ore into beryllium sulphide, treating the reaction mass in a'gaseous chlorinating atmosphere so as to convert the beryllium sulphide into beryllium chloride, isoiatingthe beryllium chloride by distillation, heating the beryllium chloride thus isolated with sulphurous vapour in the presence of a substantial proportion of carbonaceous material so as to convert the beryllium chloride into beryllium sulphide, and reducing the beryllium sulphide thus obtained to beryllium metal.

4. In a process for treating beryllium ore for the production 01' beryllium therefrom, sulphidising the ore in the presence of a substantial proportion of carbonaceous material at a temperature ranging from about 1800 C. to about 2000 C.

whereby volatilization of the beryllium sulphide sufficient to convert the greater part of the beryllium in the ore into beryllium sulphide, converting the beryllium sulphide thus formed into beryllium chloride, isolating the beryllium chloride thus formed and converting it again into beryllium sulphide, and heating the beryllium sulphide thus obtained in a non-oxydising atmosphere with a metal the sulphide of which has a heat of formation exceeding that of beryllium sulphide so as to reduce the beryllium sulphide to beryllium metal.

7 5. In a process for treating beryllium ore for the production of beryllium therefrom, sulphidising the ore in the presence of a substantial proportion of carbonaceous material at a temperature ranging from about 1800 C. to about 2000 C. whereby volatilization of the beryllium sulphide is substantially prevented and for a length of time suflicient to convert the greater part of the beryllium in the ore into beryllium sulphide, converting the beryllium sulphide thus formed into beryllium chloride, isolating the beryllium chloride thus formed and converting it again into beryllium sulphide, and heating the beryllium sulphide thus obtained in a non-oxidising atmosphere with an excess of a metal the sulphide of which has a heat of formation exceeding that of beryllium sulphide so as to produce an alloy of beryllium and the-particular metal 'used. I

6. In a process for treating beryllium ore for the production of beryllium therefrom, sulphidising the ore in the presence of a substantial proportion of carbonaceous material at a temperature ranging from about 1800 C. to about 2000 C. whereby volatilization of the beryllium sulphide is substantially prevented and for a length of time suflicient to convert the greater part of the beryllium in the ore into beryllium sulphide, converting the beryllium sulphide thus formed into beryllium chloride, isolating the beryllium chloride thus formed and converting it again into beryllium sulphide, and heating the beryllium sulphide thus obtained with a metal the sulphide of which-has a heat of formation exceeding that of beryllium sulphide in the presence of a flux comprising beryllium fluoride so as to reduce the beryllium sulphide to beryllium metal.

'7. In a process for treating beryllium ore for the production of beryllium therefrom, sulphidising the ore in the presence of a substantial proportion of carbonaceous material at a temperature ranging from about 1800 C. to about 2000 C.

whereby volatilization of the beryllium sulphide mixture with a metal such as aluminium'the beryllium in the ore into beryllium sulphide, converting the beryllium sulphide thus formed into beryllium chloride, isolating the beryllium chloride thus formed and converting it again into beryllium sulphide, and heating the beryllium sulphide thus. obtained with a mixture of copper and a metal such as aluminium the sulphide of which has a heat of formation exceeding that of beryllium sulphide.

9. In a process for treating beryllium ore for the production of beryllium therefrom, sulphidising the ore in the resence of a substantial proportion of carbonaceous material at a temperature ranging from about 1800 C. to about 2000 C. wherebyvolatilization of the beryllium sulphide is substantially prevented and for a length of time sufiicient to convert the greater part of the beryllium in the ore into beryllium sulphide, converting the beryllium sulphide thus formed into beryllium chloride, isolating the beryllium chloride thus formed and converting itagain into beryllium sulphide, heating the beryllium sulphide thus obtained with a metal the sulphide of which has a heat of formation exceeding that of beryllium sulphide so as to reduce the beryllium sulphide to beryllium metal, distilling the beryllium metal thus obtained, and condensing the beryllium vapour.

10. In a process for treating beryllium ore for the'production of beryllium therefrom, sulphidising the ore in the presence of a substantial proportion of carbonaceous material at a temperature ranging from about 1800 C. to about 2000 C. whereby volatilization of the beryllium sulphide is substantially prevented and for a length of time sufficient to convert the greater part of the beryllium in the ore into beryllium sulphide, converting the beryllium sulphide thus formed into beryllium chloride, isolating the beryllium chloride thus formed and converting it again into beryllium sulphide, heating the beryllium sulphide thus obtained with a metal the sulphide of which has 'a heat of formation exceeding that 'of beryllium sulphide so as to reduce the beryllium sulphide to beryllium metal, distilling the beryllium metal thus obtained, and condensing the beryllium vapour in a molten charge of metal. a

11. In a process for treating beryllium ore for the production of beryllium therefrom, said process comprising forming beryllium sulphide by sulphidizing said ore in the presence of a substantial proportion of carbonaceous material at a temperature ranging from about 1800 C. to

about 2000 C. whereby volatilization of the beryli lium sulphide is substantially prevented and thereafter subjecting the beryllium sulphide thus formed to treatment for the production of metallic beryllium therefrom.

the production of beryllium therefrom, said process comprising forming beryllium sulphide by thoroughly mixing said ore and a substantial proportion of carbonaceous material heating the thus obtained mixture in the presence of sulphurous vapours to a temperature ranging from about 1800 C. to about 2000 C. whereby volatilization of the beryllium sulphide is substantially prevented and thereafter subjecting the.

beryllium sulphide thus formed to treatment for the production of metallic beryllium therefrom.

DANIEL GARDNER.