BARITE 



77 



1920 



1970 



I 



Figure 10. — Barite, world production and U.S. production 

 and consumption, 1919-71. 1. Post-World War I depres- 

 sion. 2. Barite drilling mud introduced and accepted. 3. 

 Economic depression. 4. World War II. 5. World economic 

 recession. 



Barite has been or could be produced as a by- 

 product or coproduct of some fluorspar, base and 

 precious metal, and rare-earth deposits. These 

 sources of barite have not been greatly utilized for 

 many reasons. Some deposits are too far from 

 markets, or the additional milling operation cannot 

 be handled by existing mills. The barite is too 

 irregularly disseminated in some deposits, and the 

 demand for the major product too variable to guar- 

 antee the barite user a steady supply in others. 

 Economic changes may bring much of this barite 

 into future markets. 



Most of the barite mined in the United States has 

 been mined in open pits. The mining of residual 

 deposits has brought on the need to rehabilitate 

 many acres of worked ground. In many areas of 

 shallow residual deposits, rehabilitation is not diffi- 



cult, but any costs will ultimately be paid by the 

 consumer. 



GEOCHEMISTRY 



Recent estimates of the abundance of barium in 

 the earth's crust (Parker, 1967; Lee and Yao, 1970) 

 suggest that the value lies in the range of 300-500 

 ppm (parts per million equals grams per metric ton ; 

 1 ppm equals 0.0001 percent) . In igneous rocks, the 

 basalts contain as little as 100 ppm Ba; granites 

 commonly contain 700-800 ppm Ba; syenites and 

 some of the more potassic igneous rocks contain as 

 much as 3,000-5,000 ppm Ba. The role of barium in 

 the crystallization of igneous rocks has been dis- 

 cussed by Dunham and Hanor (1967). Among the 

 sedimentary rocks, shale generally contains the most 

 barium (500-1,000 ppm) and limestone contains 

 the least (commonly less than 200 ppm). The bar- 

 ium content of sandstone varies widely, from a few 

 to several hundred parts per million. 



The large size of the barium ion in its common 

 valence state (Ba+-, 1.43 angstrom units) makes 

 isomorphous substitution possible only with stron- 

 tium (Sr+% 1.27) and generally not with the other 

 members of the elements of Group 2A of the periodic 

 table (Ca+% 1.06; Mg+% 0.78). Among the other 

 elements that occur with barium in nature, substi- 

 tution is common only with potassium (K+, 1.33), 

 but not with the smaller ions of Na, Fe, Mn, Al, and 

 Si in their most common valence states. This ex- 

 plains why the potassium-rich igneous rocks con- 

 tain the greatest amounts of barium. The barium 

 commonly substitutes for potassium in the minerals 

 of the feldspar and mica groups. 



Unlike many other common metals, the sulfide of 

 barium is water soluble, the sulfate is virtually in- 

 soluble in distilled water, and, as the chloride the 

 element is easily transportable. Barium, therefore, 

 is mobilized, transported, and concentrated under 

 diff'erent conditions from those which govern the 

 course of many base and ferrous metals in the geo- 

 chemical cycle. 



The geochemical cycle of barium begins with its 

 arrival in the upper crust of the earth as a result 

 of volcanic activity and the emplacement of intru- 

 sive igneous rocks and any attendant vein systems. 

 The mechanical and chemical disintegration of ig- 

 neous rocks releases barium to the sedimentary 

 cycle through which it is carried seaward as fine 

 particles of mineral material, or as ions absorbed 

 on particles of clay size, or perhaps attached to 

 negatively charged sols, such as Mn(0H)4. In the 

 sea, ionic barium will combine readily with avail- 

 able sulfate anions to form a precipitate of barium 



