Ammonium Uranyl Carbonate MSDS

Tetraammonium uranyl tricarbonate, of uranium depleted in uranium 235
Uranate(4-), tris[carbonato(2-)-O,O']dioxo-, tetraammonium, (HB-8-22-111'1'1''1'') Azanium uranium carbonate
Formula	(NH4)4(UO2)(CO3)3
Structure
Uses	Substance is used in uranium yellow glazes.

Registry Numbers and Inventories.
CAS	18077-77-5
NIH PubChem CID	3015006
EC (EINECS/ELINCS)	241-988-5
UN (DOT)	2909
Merck	12,602
Beilstein/Gmelin	NA

Properties.
Formula	C3H16N4O11U
Formula mass	522.21

Hazards and Protection.
Storage	Keep in a cool, dry, dark location in a tightly sealed container or cylinder. Keep away from incompatible materials, ignition sources and untrained individuals. Secure and label area. Protect containers/cylinders from physical damage.
Handling	All chemicals should be considered hazardous. Avoid direct physical contact. Use appropriate, approved safety equipment. Untrained individuals should not handle this chemical or its container. Handling should occur in a chemical fume hood.
Protection	Wear appropriate protective gloves, clothing and goggles.
Respirators	Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks	Do not touch damaged packages or spilled material. Cover liquid spill with sand, earth or other noncombustible absorbent material. Cover powder spill with plastic sheet or tarp to minimize spreading. Contact radiation safety officer.
Stability	No data.

Fire.
Fire fighting		Presence of radioactive material will not influence the fire control processes and should not influence selection of techniques. Small Fires: Dry chemical, carbon dioxide, water spray or regular foam. Large Fires: Water spray, fog (flooding amounts).
Fire potential		May burn but does not ignite readily.

Health.
Exposure effects
Ingestion	See Inhalation.
Inhalation	Minimal risk if packaging remains intact. Package damage can result in a measurable release of radiation but the risk is still low.
Skin	See Inhalation.
Eyes	See Inhalation.
First aid
Ingestion	Medical problems take priority over radiological concerns. Use first aid treatment according to the nature of the injury. Do not delay care and transport of a seriously injured person.
Inhalation	Apply artificial respiration if victim is not breathing. Administer oxygen if breathing is difficult. See Ingestion.
Skin	Immediately flush with running water for at least 20 minutes. See Ingestion.
Eyes	Immediately flush with running water for at least 20 minutes. See Ingestion.

Transportation
UN number	2909
Response guide	161
Hazard class	7
USCG CHRIS Code	RAD

Ammonium uranyl carbonate(UO₂CO₃·2(NH₄)₂CO₃) is known in the uranium processing industry as AUC and is also called uranyl ammonium carbonate. This compound is important as a component in the conversion process of uranium hexafluoride (UF₆) to uranium dioxide (UO₂). The ammonium uranyl carbonate is combined with steam and hydrogen at 500-600°C to yield UO2. In another process aqueous uranyl nitrate, known as uranyl nitrate liquor (UNL) is treated with ammonium bicarbonate to form ammonium uranyl carbonate as a solid precipitate. This is separated from the solution, dried with methanol and then calcinated with hydrogen directly to UO₂ to obtain a sinterable grade powdwer. The ex-AUC uranium dioxide powder is free-flowing, relatively coarse (10 µ) and porous with specific surface area in the range of 5m²/g and suitable for direct pelletisation, avoiding the granulation step. Conversion to UO₂ is often performed as the first stage of nuclear fuel fabrication.

The AUC process is followed in South Korea and Argentina. In the AUC route, calcination, reduction and stabilization are simultaneously carried out in a vertical fluidized bed reactor. In most countries, sinterable grade UO₂ powder for nuclear fuel is obtained by the ammonium diuranate (ADU) process, which requires several more steps.

Ammonium uranyl carbonate is also one of the many forms called yellowcake in this case it is the product obtainded by the heap leach process.