Heavy spar

Heavy oil conversion Heavy oils Heavy spar Heavy water... 

Barium [7440-39-3] Ba, is a member of Group 2 (IIA) of the periodic table where it Hes between strontium and radium. Along with calcium and strontium, barium is classed as an alkaline earth metal, and is the densest of the three. Barium metal does not occur free in nature however, its compounds occur in small but widely distributed amounts in the earth s cmst, especially in igneous rocks, sandstone, and shale. The principal barium minerals are barytes [13462-86-7] (barium sulfate) and witherite [14941-39-0] (barium carbonate) which is also known as heavy spar. The latter mineral can be readily decomposed via calcination to form barium oxide [1304-28-5] BaO, which is the ore used commercially for the preparation of barium metal. 

The first report concerning barium compounds occurred in the early part of the seventeenth century when it was noted that the ignition of heavy spar gave a peculiar green light. A century later, Scheele reported that a precipitate formed when sulfuric acid was added to a solution of barium salts. The presence of natural barium carbonate, witherite [14941-39-0] BaCO, was noted in Scodand by Withering. 

Barite [13462-86-7], natural barium sulfate, BaSO, commonly known as barytes, and sometimes as heavy spar, tiU, or cawk, occurs in many geological environments in sedimentary, igneous, and metamorphic rocks. Commercial deposits are of three types vein and cavity filling deposits residual deposits and bedded deposits. Most commercial sources are replacement deposits in limestone, dolomitic sandstone, and shales, or residual deposits caused by differential weathering that result in lumps of barite enclosed in clay. Barite is widely distributed and has minable deposits in many countries. 

Schwer-spat, m. heavy spar, barite, -stein, m. scheelite. 

Occurrence. Barium occurs mainly as witherite (BaC03) and baryte or heavy spar (BaS04). 

Barium - the atomic number is 56 and the chemical symbol is Ba. The name is derived from the Greek barys for heavy since it was found in the mineral heavy spar (BaSOJ. It was discovered by the Swedish pharmacist and chemist Carl Wilhelm Scheele in 1774 and it was first isolated by the British chemist Humphry Davy in 1808. 

Barium was discovered in 1808 by Sir Humphrey Davy. Its abundance in the earth s crust is about 0.0425% (425 mg/kg). The element also is found in sea water at trace concentration, 13 J,g/L. It occurs in the minerals barite or heavy spar (as sulfate) and witherite (as carbonate). 

Synonyms barite baryte heavy spar blanc fixe... 

Barium sulfate is widely distributed in nature and occurs as the mineral barite (also known as barytes or heavy spar). It often is associated with other metallic ores, such as fluorspar. Barites containing over 94% BaS04 can be processed economically. 

Early in the seventeenth century Vincenzo Casciarolo, a shoemaker and alchemist in Bologna, noticed that when heavy spar is mixed with a combustible substance and heated to redness, the resulting mixture, which became known as the "Bologna stone, emits a phosphorescent glow. 

Baryta was first distinguished from lime in 1779 by Scheele, who prepared it from heavy spar, a naturally occurring barium sulfate. He reduced the sulfate to the sulfide by heating a sticky, pasty mixture of heavy spar, powdered charcoal, and honey. After decomposing the barium sulfide with hydrochloric acid, he added excess potassium carbonate to precipitate the barium as the carbonate (15). 

In 1783 he published an annotated translation of Torbem Bergman s Sciagraphia regni mineralis, and in the following year he communicated to the Philosophical Transactions his Experiments and observations on terra ponderosa (barium carbonate, or witherite) (96). He stated that the specimen he examined came from a lead mine at Alston Moor, on the Pennines of Cumberland. Although he at first mistook it for heavy spar (barite) he soon found it to be a compound of heavy earth (barium oxide) and fixed air (carbon dioxide) (97). 

In 1790 Dr. Adair Crawford (1748—1795) published a paper on The medicinal properties of the muriated barytes (barium chloride) (18). The muriated barytes exhibited in St. Thomas s Hospital since the month of May, 1789, said he, was obtained by the decomposition of the heavy spar. Having procured some specimens of a mineral which is sold at Strontean [sic], in Scotland under the denomination of aerated barytes, I was in hopes that the salt might be formed with less difficulty by immediately dissolving that substance in the muriatic acid. It appears, however, from the following facts, which have been verified by the experiments of my assistant, Mr. Cruikshank, as well as by my own, that this mineral really possesses different properties from the terra ponderosa [baryta] of Scheele and Bergman (49). 

In 1768 A. S. Marggraf made the first chemical investigation of fluorite, distinguished it from heavy spar and selenitic spar (sulfates of barium and calcium), and showed that it is not a sulfate (77, 78). When he distilled pulverized fluorspar with sulfuric acid from a glass retort, the glass was badly attacked and even perforated. He noticed that an earth [silica] appeared in the receiver, and therefore concluded that the sulfuric acid had liberated a volatile earth from the fluorspar (77). 

Baryta.—This substance, iu the form known as heavy spar—Ba 0, S 0 —is sometimes added to the constituents of common bottle-glass, to render it more easy of fusion. 

Baryta Sulphate of Baryta 1 Heavy Earth Vitriol of Heavy earth Heavy spar... 

BARITE. The mineral barite is barium sulfate, BaSOa crystallizing in the orthorhombic system. It may occur as tabular crystals, in groups, or lamellar, fibrous and massive, Barite has two perfect cleavages, basal and prismatic hardness, 3-3.5 specific gravity, 4.5, which has led to the term heavy spar, occasionally used for this mineral. Its luster is vitreous streak, white color, white to gray, yellowish, blue, red and brown transparent to opaque, it sometimes yields a fetid odor when broken or when pieces are rubbed togedier, due probably to the inclusion of carbonaceous matter. It is used as a source of barium compounds. 

Barium occurs chiefly as sulfate (barite, barytes, heavy spar, H.iSO(i. and. of less importance, carbonate (witherite. RaCf)3). Georgia and Tennessee are the principal producing states. The sulfate is transformed into chloride, and the electrolysis of the fused chloride yields barium metal. See also Barite and Witherite. Barium ores are mined chiefly as a source of barium compounds because very little metallic barium is consumed commercially. The metal is obtained by thermal reduction of the oxide, using aluminum metal at a high temperature and under vacuum in a closed retort 4BaO + 2A1 > BaOAI Ot+ 3Ba. The gaseous barium produced is recovered by condensation. 

Yellow ochres are earths composed essentially of clay coloured by hydrated ferric oxide they may contain siliceous sand, calcium carbonate, small proportions of manganese oxides, and sometimes basic ferric sulphate and calcium and barium sulphates. Chalk, gypsum and heavy spar may be added fraudulently and the colour may be " improved by artificial organic dyes, vegetable colours or chrome yellow. 

Minium may contain various impurities derived from the raw materials of its manufacture, e.g., calcium salts and oxides of iron and copper. It may be adulterated with day, chalk, gypsum, heavy spar, lead sulphate, brickdust, ochre and other colours with a basis of ferric oxide, and artificial organic dyes. 

Cinnabar and vermilion usually contain only small proportions of impurities from the prime materials vermilion may also contain impurities due to the method of preparation, namely, small quantities of metallic mercury, mercuric nitrate and free sulphur. These products are, however, often adulterated with ferric oxide, minium, chrome red, brickdust, gypsum, heavy spar, clay, ammonium chloride, dragon s blood, carmine and artificial organic dyes. Sometimes also arsenic and antimony sulphides are added to modify the colour. 

It may contain, as impurities or as additions, other cadmium compounds, zinc compounds and free sulphur, and it may also be adulterated with chrome yellow, cinnabar, arsenic sulphide, heavy spar and gypsum. 

This is a complex compound of aluminium and sodium silicate and sodium sulphide. The typical and most common ultramarine is blue ultramarine, which forms a very fine powder (microscopically crystalline) of a pure blue, reddish blue or greenish blue colour according to the proportions of the components and the method of preparation ultramarines of other tints, especially green and violet ultramarines, are also made. Ultra-marine may be adulterated with gypsum, chalk, clay, heavy spar, zinc white and magnesium carbonate and may also be mixed with glycerine and glucose. 

Extraneous Substances.—From 1 to 2 grams of the ultramarine are boiled with hydrochloric acid and filtered. If the ultramarine is pure, the insoluble residue is composed exclusively of silica with small quantities of alumina and a little sulphur if the sample contains barium sulphate or alumina in considerable quantity, it is adulterated with heavy spar or clay. 

They may contain as impurities, small quantities of alkali, sulphates and chlorides and are often adulterated with kaolin, heavy spar, gypsum, chalk, white lead, zinc white, magnesia, starch, etc. 

It is often adulterated with cochineal exhausted of its colouring matter and then dried, or moistened with solutions of dyeing extracts (especially red wood) and is frequently mixed with talc, gypsum, or heavy spar. It is sometimes mixed also with leaden fragments or filings. The tests to be made are as follows ... 

Synonyms Barium monoxide barium protoxideb k Artificial heavy spar artificial barite barytes blanc fixe precipitated barium sulfate sulfuric acid, barium saltl,q No data... 

SYNS ACTYBARYTE ARTIFICIAL BARITE ARTinCIAL HEAVY SPAR BAKONTAL BARIDOL BARITE BARITOP BAROSPERSE BAROTRAST BARYTA VCTIITE BARYTES BAYRITES BLANC FIXE C.1.77120 C.I. PIGMENT WHITE 21 CITOBARYUM COLONATRAST ENAMEL WHITE ESOPHOTRAST EWEISS E-Z-PAQUE FINEMEAL LACTOBARYT LIQUIBARINE MACROPAQUE NEOBAR ORATRAST PERMANENT WHITE PRECIPITATED BARIUM SULPHATE RAYBAR REDI-FLOW SOLBAR SULFURIC ACID, BARIUM SALT (1 1) SUPRAMIKE TRAVAD UNIBARYT... 

---