3,717,437 United States Patent Office Patented Feb. 20, 1973 1 2 3,717,437 pure aqueous sulfuric acid solution containing dissolved CRYSTALLIZATION OF BERYLLUM SULFATE beryllium sulfate which comprises first treating the solu James K. Grunig, Rodney J. Anderson, and Bess L. Vance, tion to form a solution containing about 50% to 55% Tucson, Ariz, assignors to The Anaconda Company by weight of sulfuric acid. The treated solution is then Filed Dec. 14, 1970, Ser. No. 97,841 cooled to a temperature sufficiently low to crystallize Int. Cl, C22b 59/00 beryllium sulfate therefrom and produce an acid mother U.S. CI. 23-24 B 16 Claims liquor containing about 58% to 62% by weight Sulfuric acid. The acidic mother liquor is thereafter separated from the beryllium sulfate crystals and the beryllium sulfate ABSTRACT OF THE DISCLOSURE O crystals are calcined to form beryllium oxide of suf A process for the recovery of substantially pure beryl ficiently high purity for most uses. If a higher purity beryl lium oxide from an impure aqueous Sulfuric acid solution lium oxide is desired, then after separating the acidic containing dissolved beryllium sulfate by crystallizing mother liquor from the beryllium sulfate crystals and prior beryllium sulfate from the solution after concentrating to calcining, the separated beryllium sulfate crystals are it to about 50% to 55% by weight of sulfuric acid and 15 redissolved in an aqueous solution and treated such that, then calcining the crystallized beryllium Sulfate. upon recrystallization and mother liquor, separation, BeSO2HaO or BeSO-4HaO crystals are produced. Af ter this recrystallization and separation, the beryllium sul BACKGROUND OF THE INVENTION fate crystals would be subject to the calcining operation Several processes have been developed for the extrac to form high purity beryllium oxide. tion of beryllium values from beryllium-bearing materials. A number of beryllium-bearing materials are suitable By these known prior art processes, it has been dificult to for treatment by the method of the present invention. separate compounds of Such material as aluminum, iron, These materials include both low and medium grade beryl magnesium, calcium and fluorine from the beryllium lium containing ores, for example, ores from the Spor compound component. Hence, a pure final beryllium prod 25 Mountain Region in the United States. Beryllium is uct is relatively costly to produce. thought to occur in these ores mainly as bertrandite For certain uses of beryllium oxide, e.g., in nuclear re (4BeO-2SiOa-28H2O) and/or beryliferous saponite. In actors, almost complete freedom from such contamina contrast to bertrandite, beryl (3BeO· AlaOa-6SiOa) and tion is required. Further high purity beryllium oxide finds phenacite (BeaSiO), which are other forms of naturally importance as a starting material for electrowinning eX 30 occurring beryllium, are not readily soluble in moderate tremely pure beryllium metal from a molten beryllium salt acid concentrations. However, these materials may be solution. As a result, there is a relatively large demand rendered acid soluble by such prior art processes as fiuo for a practical and economical process capable of uni ride sintering and alkali fusion. The invention is not formly producing beryllium oxide which is substantially limited to these particular ores but includes within its free from contamination. 35 scope any beryllium-bearing material which is either solu ble or which may be rendered soluble in sulfuric acid to SUMMARY OF THE INVENTION form a beryllium sulfate solution, regardless of the par We have discovered a method for producing a high yield ticular beryllium concentration. of substantially pure beryllium oxide having superior The beryllium ore or other raw material containing physical characteristics in such quantity and of such qual 40 the beryllium is first treated by any of the prior art ity as to make it an economically feasible and attractive methods to produce an aqueous sulfuric acid solution con process. We have discovered the favorable concentrations taining dissolved beryllium sulfate. This solution, which of sulfuric acid and beryllium sulfate to sufficiently de may contain a substantial amount of impurities, is the press the solubility of beryllium sulfate to a point where starting solution for the process of our invention. The upon after cooling the beryllium sulfate is substantially 45 aqueous solution can, for example, be obtained from the insoluble and precipitates out as crystals which upon sub eluates of a liquid-ion exchange (LIX) process, a resin sequent calcination yield beryllium oxide having a purity in column (RIC) process, or a leaching process. In com of 99-H%. monly assigned and co-pending application Ser. No. 710,- It is therefore an object of this invention to provide a 098 filed Mar. 6, 1968 and entitled Extraction of Beryl process which will result in a high yield extraction of 50 lium from Ores, there is disclosed an extraction process beryllium oxide from beryllium-bearing materials. for obtaining pure beryllium compounds from low grade It is also an object of this invention to provide a feasible beryllium ores. The beryllium ore is first leached with a process which will result in the production of an extremely mineral acid and then the pH of the leach solution is pure beryllium oxide. raised to about a pH of 4.0 to precipitate the major im It is a further object of this invention to provide an 55 purities. Beryllium hydroxide is then precipitated by rais economical process for producing beryllium oxide from ing the pH of the solution to about a pH of 8.0-8.4. In beryllium-bearing materials which process permits the easy accordance with the requirement for the present inven separation of the beryllium values from other compounds tion, the beryllium hydroxide from this process would which heretofore have been very difficult to separate. 60 then be partially dried and then dissolved with sulfuric Accordingly, to accomplish the above objects and other acid to a slightly acid solution of beryllium sulfate. This objects, the present invention contemplates a process for solution could well be used as the starting solution in our recovering substantially pure beryllium oxide from an im invention. 3,717,437 3 4 BRIEF DESCRIPTION OF THE DRAWING G./i. FIG. 1 illustrates a flow sheet of one process for ob BeSO4 ------------------------------------ 168.0 Ala(SO4)3 --------------------------------- 27.5 taining pure beryllium oxide in accordance with the in MgSO4 ------------------------------------ 4.05 vention. CaSO4 ------------------------------------- 4.50 FIG, 2 illustrates an alternate process for obtaining MnSO4 ------------------------------------ 1.88 pure beryllium oxide. FeSO4 ------------------------------------ 22 DESCRIPTION OF THE PREFERRED F ---------------------------------------- · EMBODIMENTS HaO -------------------------------------- 508 10 HaSO4 ------------------------------------ 760 Referring to FIG. 1, the starting solution consists of an Wt. percent H2SO4, 52. extract from a resin in column (RIC) process used for Such dilution serves to allow some crystal growth while recovering beryllium values. According to the invention, still serving to substantially completely depress the beryl the extract solution should have a concentration by lium sulfate solubility in the crystallization mother liquor weight of sulfuric acid of at least about ten times but less at conveniently attainable emperatures during subsequent than twenty-five times as great as that of the dissolved crystallization. beryllium sulfate, expressed as beryllium oxide. It has After the solution has been diluted to the degree re been found that the amount of extract solution within quired, it is transferred to a crystallizing tank where the this range contains a sufficient liquid volume to solubilize temperature of the solution may be reduced at a con any impurities, such as aluminum or magnesium etc., 20 trolled rate. Since the solubility of beryllium sulfate de for removal during the subsequent steps of the method creases with decreasing temperature, cooling of the solu described herein and yet is not too large to dilute the tion causes the beryllium sulfate to crystallize from the beryllium to such an extent to make the recovery un acidic solution. The beryllium sulfate is preferably cooled economical. Therefore, if necessary, the acid concentra to a temperature of about 120° F. and is held at such a tion is adjusted to form an aqueous solution which con 25 temperature for a time sufficient to allow for crystalliza tains a weight ratio of HaSO4:BeO in the above range. tion of as much of the beryllium sulfate as will separate. The solution also contains dissolved impurities carried When an extract solution having a sulfuric acid concen through from the ore or other raw material used. A typi tration within the range of about 50% to 55% by weight cal sampling of the extract, after it has been adjusted to is cooled to crystallize beryllium sulfate from the acid the desired HaSO4:BeO ratio, contains about substantial 30 solution, the acidic mother liquor produced therefrom 1y the following: will have a sulfuric acid concentration of between about G./i. 58% to 62% by weight. It was found that, at a mother BeSO4 ------------------------------------ 86.3 liquor acid concentration within the aforementioned Ala(SO4)3 --------------------------------- 14.1 range, the solubility of beryllium sulfate in the extract MgSO4 ------------------------------------