Name | Barium sulfate |
Synonyms | Baryte Barite baritop Barytes baritopp barium100 Blanc fixe baritop100 C.I. 77120 bariumandreu Bariumsulfate Barium sulfate baritopgpowder Barium sulphate baritogendeluxe bariumsulfuricum barium sulfuricum barite,artificial C.I. Pigment White 21 Bariumsulfate,precipitated pricipitated Barium sulphate barium sulphate PRECIPITATED |
CAS | 7727-43-7 13462-86-7 |
EINECS | 231-784-4 |
InChI | InChI=1/Ba.H2O4S.2H/c;1-5(2,3)4;;/h;(H2,1,2,3,4);;/p-2/rBaH2.H2O4S/c;1-5(2,3)4/h1H2;(H2,1,2,3,4)/p-2 |
Molecular Formula | BaO4S |
Molar Mass | 233.39 |
Density | 4.5 |
Melting Point | 1580 °C |
Boling Point | decomposes at 1580℃ [KIR78] |
Water Solubility | 0.0022 g/L (50 ºC) |
Solubility | water: insoluble |
Appearance | White powder |
Specific Gravity | 4.5 |
Color | White to yellow |
Exposure Limit | ACGIH: TWA 5 mg/m3OSHA: TWA 15 mg/m3; TWA 5 mg/m3NIOSH: TWA 10 mg/m3; TWA 5 mg/m3 |
Solubility Product Constant(Ksp) | pKsp: 9.97 |
Merck | 14,994 |
PH | 3.5-10.0 (100g/l, H2O, 20℃)suspension |
Storage Condition | Storage temperature: no restrictions. |
Stability | Stable. |
Sensitive | Easily absorbing moisture |
MDL | MFCD00003455 |
Physical and Chemical Properties | properties colorless orthorhombic crystal or white shaped powder. colorless orthorhombic crystal or white amorphous powder. Relative density 4.50 (15 degrees C). Melting point 1580 °c. Polycrystalline transformation occurs at around 1150 °c. Significant decomposition began at about 1400 °c. Chemical stability. Practically insoluble in water, ethanol and acids. Soluble in hot concentrated sulfuric acid, dry easy to agglomerate. 600 C with carbon can be reduced to barium sulfide. |
Use | It is mainly used as a weighting agent for oil and natural gas drilling mud, and is also an important mineral raw material for extracting metal barium and preparing various barium compounds. The most important barium compounds in industry are barium carbonate, barium chloride, sulfuric acid, barium nitrate, barium hydroxide, barium oxide, barium peroxide, barium chromate, Barium manganate, barium chlorate, lithopone, barium polysulfide, etc. Barium compounds are widely used as raw materials and fillers for rubber, plastics, pigments, coatings, paper making, textiles, paints, inks, electrodes; Used as barium-based grease, oil refining, beet sugar, Rayon raw materials; Used as pesticides, sterilants, rodenticides, explosives, Green pyrotechnic, signal bomb, tracer, medical X-ray photography indicators; Also used in glass, ceramics, leather, electronics, building materials, metallurgy and other departments. Barium metal can be used for television and real |
Hazard Symbols | Xn - Harmful |
Risk Codes | R20/21/22 - Harmful by inhalation, in contact with skin and if swallowed. R36/37/38 - Irritating to eyes, respiratory system and skin. |
Safety Description | S22 - Do not breathe dust. S24/25 - Avoid contact with skin and eyes. S36 - Wear suitable protective clothing. S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. |
WGK Germany | - |
RTECS | CR0600000 |
TSCA | Yes |
HS Code | 28332700 |
Toxicity | LD50 orally in Rabbit: > 20000 mg/kg |
inhalation can cause chest tightness, chest pain, Cough, etc. It is irritating to eyes. Long-term inhalation can cause barium pneumoconiosis. Staff should be protected and the workplace should be well ventilated. If the skin and eyes are touched, wash with running water immediately. Keep away from fire and heat source. Packaging is required to be sealed and not to be in contact with air. Should be stored separately from reducing agent, flammable, combustible, metal powder, etc.
pH range of acid-base indicator discoloration | 7 |
EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
Chemical properties | barium sulfate, also known as barite, chemical formula BaSO4, colorless or white orthorhombic crystal system. Relative molecular mass 233.40. Relative density 4.5(15 degrees C). Melting point 1580 °c. Refractive index 1.637. When heated to 1149 ° C., monoclinic crystals become formed, and the refractive index at this time is 1.649. Almost insoluble in water, 18 ℃ for 0.00022, 100 ℃ for 0.00041, slightly soluble in concentrated sulfuric acid; Soluble in alkali metal carbonate solution, into barium carbonate; Insoluble in other acid and alkali. In nature, it exists in the form of barite minerals. The natural mineral is called barite. Co-heated with carbon (pulverized coal) to 800 °c, reduced to soluble barium sulfide and carbon monoxide. With the ability to strongly absorb X-rays, X-rays cannot be transmitted, and can be used as a medicine (barium meal) for X-ray fluoroscopy of the stomach. Barium sulfate is the only non-toxic barium salt. Used in analysis reagents, electronics, instrumentation, metallurgy and other industries, used as white pigment, gastrointestinal X-ray contrast agent, copper smelting flux, drilling mud specific gravity increasing agent and rubber, paper, white filler of plastic. Obtained from the reaction of sulfuric acid with barium chloride. type I barium sulfate: white loose fine powder, odorless, tasteless. Type II barium sulfate: refined from barium sulfate of barite family, According to the dry product calculation, containing barium sulfate should not be less than 97%, for the white loose fine powder, odorless, tasteless. Barium sulfate (type I and type II) are insoluble in water, organic solvents, acid or sodium hydroxide, containing 58.84% barium. Figure 1 is a white barium sulfate powder. This information was edited by chemical book Xiaonan (2015-09-02). |
indication | barium sulfate dry suspension is suitable for single and double contrast examination of esophagus, stomach, duodenum, small intestine and colon, can also be used for double contrast examination of digestive tract. Oral Suspension, viscous for esophageal radiography, dilute for stomach and intestinal examination, called barium meal examination. Dilute suspension can also be rectal perfusion, Colon contrast called barium enema. Barium sulfate mucilage for injection can be used for bronchography and brain abscess radiography. |
pharmacokinetics | barium sulfate is not absorbed after oral administration or infusion into the gastrointestinal tract, its discharge time and food through the time is approximately the same, non-irritating, non-toxic, basically does not affect the gastrointestinal function, for good X-ray contrast agent. After entering the bronchus, most of them cough out, a small amount of them enter the alveoli, deposit in the alveolar wall, or be phagocytosed by phagocytes and transported to the pulmonary interstitium and lymphatic system, but the speed is very slow, so it is not suitable for bronchography. |
Diagnostic Imaging Drugs | barium sulfate is not absorbed in the gastrointestinal tract, maintain high concentration, block X-ray transmission, clear imaging, non-toxic to the human body, therefore, it is suitable for esophageal and gastrointestinal radiography. Barium salt can absorb a large amount of X-ray, after entering the gastrointestinal tract and the surrounding tissue structure in the X-ray image to form a density contrast, thus showing the location, contour, shape, surface structure and functional activity. Fine and uniform type barium is mostly synthetic barium, fine and uniform particles, mostly round, light weight, slow and consistent settlement, suitable for esophagus, stomach, duodenum, small intestine, Colon single, double Contrast radiography. Because of the low optimal concentration of fine and uniform type barium, the fine structure of the gastric mucosa such as the gastric area is not as good as the uneven thickness type. |
usage and dosage | barium sulfate dry suspension: add water to prepare suspension with appropriate concentration and temperature before use, the usual introduction methods include oral administration, small intestine enema and colon enema. (1) Esophageal examination: Oral (concentration 60% ~ 250%)15 ~ 60mL, can immediately observe the esophagus and its peristalsis; Before taking barium, first take gas production drugs, it can be used for double contrast examination of esophagus. (2) double contrast examination of stomach and duodenum: fasting for more than 6h, oral gas-producing drugs, after 300 ~ 500mL of CO2 gas is produced in stomach, can first oral barium 70 ~ 200% (concentration of 250% ~), so that patients turn over a few rounds, so that barium evenly coated on the gastric mucosa can be, If necessary, add 150mL barium; For example, 20min before the contrast examination, give the patient hypotonic drugs (such as injection of anisodamine, or oral atropine, etc.), and oral gastric enzyme cleaning gastric juice, double contrast examination showed that the surface structure of gastric mucosa could be more clearly displayed. (3) gastrointestinal single contrast follow-up examination: fasting for more than 6 hours, oral 240 ~ 480mL (concentration of 40% ~ 120%) can immediately observe the morphology and peristalsis of stomach and duodenum; after 15~30min, the morphology and peristalsis of small intestine can be observed; After 1.5 hours, the morphology and peristalsis of all small intestine can be observed; the ileocecal area and right colon could be observed after 2~6H. (4) small intestine enema examination: Fasting for 8~12h, barium 800 ~ 2400mL (concentration 30% ~ 80%) The patient was directly introduced into the duodenum or proximal jejunum via a special catheter, and underwent segmental small intestine Examination. If necessary, double contrast examination was performed without single contrast examination. (5) colon enema examination: 1~3 days before the examination into the liquid or semi-liquid diet, if necessary, with a moderate amount of laxative, and 1~2H before the examination to clean the intestine; Through the anus into the colon, contrast Imaging was performed by injecting contrast agent to fill the whole colon; Fluoroscopy and radiography were performed after injection of barium, which was single Contrast radiography; Then most barium was discharged, and then gas filled colon was injected, which was double Contrast radiography; for direct colon Double Contrast radiography, first inject barium 150 ~ 60% (concentration 80% ~) through the catheter, turn the position and inject the gas, so that the barium and the gas fill the whole colon, double Contrast radiography; For good results, often before the injection of contrast agent, intramuscular or intravenous injection of glucagon or hypotonic drugs such as anisodamine. |
adverse reactions | Although barium sulfate is not toxic, but improper use can still cause Nausea, constipation, Diarrhea and other symptoms; improper use can also occur intestinal perforation, followed by peritonitis, adhesions, granuloma, severe cases can also be fatal. Therefore, it is contraindicated in esophageal hemorrhage, esophageal tracheal fistula, congenital esophageal atresia, acute gastric perforation, acute gastroenteritis, gastrointestinal hemorrhage, intestinal obstruction, etc. After a large number of barium into the lung, can cause mechanical stimulation and inflammatory response, early cause foreign body giant cells, epithelioid cells and mononuclear cell infiltration, later in the deposition of barium around the fibrosis, barium nodules were formed. Oral barium examination before 6 to 12 hours of fasting. |
precautions | 1. Acute gastrointestinal perforation or gastrointestinal bleeding, Colon infarction, acute gastroenteritis, erosive esophagitis and other patients are contraindicated. Congenital diseases such as esophageal, tracheal fistula, esophageal atresia and other patients are not allowed to check this product, you can use iodized oil or water-soluble contrast agent. 2. Barium sulfate must be in accordance with the provisions of the Chinese Pharmacopoeia purity, must not contain soluble barium salt, do not mix with barium chloride (highly toxic), so as to avoid poisoning after absorption. 3. Oral barium within 6 to 12 hours before fasting, general in the morning when fasting after taking this product check. Barium enema examination of 1 to 2 hours before the first to do a clean enema, check the first 1 days to disable laxatives. 4. Patients with symptoms of Pyloric obstruction should receive at least 2 times of gastric lavage on the day before examination. 5. Drugs with higher atomic weight, such as bismuth and calcium, are contraindicated 3 days before examination. Drugs that have effects on the stomach and intestines, such as atropine, calcium, bismuth, laxative, etc., should be banned 1 day before the examination. 6. Barium sulfate powder particle fineness and purity, should meet the requirements of pharmacopoeia. Such as self-made paste or suspension of this product, you can use the appropriate dispersant and flavor, made of suitable consistency of the preparation application. |
solubility in water (g/100ml) | grams dissolved per 100ml of water: 2.448 × 10-4/20 ℃ |
Application | barium sulfate is mainly used as a weighting agent for oil and gas drilling mud, it is also an important mineral raw material for the extraction of metal barium and the preparation of various barium compounds. The most important barium compounds in industry are barium carbonate, barium chloride, sulfuric acid, barium nitrate, barium hydroxide, barium oxide, barium peroxide, barium chromate, Barium manganate, barium chlorate, lithopone, barium polysulfide, etc. Barium compounds are widely used: barium sulfate can be used as rubber, plastic, pigment, paint, paper, textile, paint, ink, electrode raw materials and fillers; Used as barium base grease, oil refining, beet sugar, Rayon raw materials; Used as pesticides, sterilants, rodenticides, explosives, Green pyrotechnic, signal bomb, tracer, medical X-ray photography indicators; Also used in glass, ceramics, leather, electronics, building materials, metallurgy and other departments. Barium can be used as a getter and binder for TV and vacuum tubes. Alloys of barium with metals such as aluminum, magnesium, lead, and silver are used to make bearings. barium sulfate can be used as raw materials or fillers for paints, inks, plastics, rubber and storage batteries, surface coating agents for printing paper and coated paper, sizing agents for textile industry, and clarifying agents for glass products, can play the role of defoaming and increase gloss, can be used as a protective wall material for anti-radiation, also used in ceramics, enamel, spices and pigments and other industries. It is also a raw material for the manufacture of other barium salts. |
production method | The open-pit mining method is used for the residual slope deposit, and the underground mining method is used for most primary mines. See "phosphate rock" for general process flow ". The main beneficiation methods are hand separation, gravity separation, magnetic separation and flotation. The principle flow of beneficiation is as follows: mirabilite-black ash method. Reaction equation: BaSO4 + 4C → BaS + 4CO ++ BaS + Na2SO4 → BaSO4 ↓ + Na2S operation method: after the black ash leaching solution generated by the reaction of barite and pulverized coal is clarified, barium sulfide starting materials with a concentration of 14% to 17% were prepared and heated to 80 °c. After removal of calcium and magnesium, mirabilite solution was prepared to a concentration of 22%-25% and heated to 90 °c. The prepared barium sulfide solution was added to the mirabilite under stirring to carry out the reaction, and the temperature was maintained at 90 ° C. To form a barium sulfate precipitate. The end point of the reaction should be controlled so that the two solutions are equal points. After the precipitate is filtered, washed with water and washed with acid, the pH value is adjusted to 5~6 with sulfuric acid, and then filtered, dried and crushed to obtain precipitated barium sulfate product. Comprehensive Utilization of brine. Reaction equation: BaCl2 + Na2SO4 → BaSO4 ↓ + 2NaCl operation method: barium yellow halogen is reacted with mirabilite, and then acid-boiled, washed with water, separated and dehydrated, and dried to obtain barium sulfate finished product. |
category | toxic substances |
toxicity grade | low toxicity |
Acute toxicity | low toxicity of insoluble body part; Partially toxic dissolved impurities trachea-mouse LD: > 600 μl/kg |
explosive hazard characteristics | explosion with aluminum, or phosphorus |
flammability hazard characteristics | Thermal decomposition toxic sulfur oxide smoke |
storage and transportation characteristics | ventilation and low temperature drying; Storage separately from aluminum and potassium |
Occupational Standard | TWA 0.5 mg/m3; Tel 1.5 mg/m3 |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |