Praseodymium

Praseodymium - Names and Identifiers

Name	Praseodymium
Synonyms	Praseodymium PRASEODYMIUM STANDARD PRASEODYMIUM SINGLE ELEMENT STANDARD PRASEODYMIUM PLASMA EMISSION STANDARD PRASEODYMIUM, PLASMA STANDARD SOLUTION
CAS	7440-10-0
EINECS	231-120-3

Praseodymium - Physico-chemical Properties

Molecular Formula	Pr
Molar Mass	140.91
Density	6.71 g/mL at 25 °C (lit.)
Melting Point	931 °C (lit.)
Boling Point	3520 °C (lit.)
Water Solubility	Reacts with water.
Appearance	Morphological powder
Specific Gravity	6.782
Color	White
Merck	13,7797
Storage Condition	Flammables area
Sensitive	Air & Moisture Sensitive
MDL	MFCD00011174
Use	Uses Used as permanent magnet materials and non-ferrous alloy additives.

Praseodymium - Risk and Safety

Risk Codes	R17 - Spontaneously flammable in air R11 - Highly Flammable R34 - Causes burns
Safety Description	S17 - Keep away from combustible material. S7/9 - S33 - Take precautionary measures against static discharges. S16 - Keep away from sources of ignition. S45 - In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) S36/37/39 - Wear suitable protective clothing, gloves and eye/face protection. S27 - Take off immediately all contaminated clothing. S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S23 - Do not breathe vapour.
UN IDs	UN 3208 4.3/PG 1
WGK Germany	3
FLUKA BRAND F CODES	1-10
TSCA	Yes
HS Code	28053090
Hazard Class	8
Packing Group	III

Praseodymium - Upstream Downstream Industry

Downstream Products

Praseodymium(III) nitrate hexahydrate
Praseodymium oxide

Praseodymium - Introduction

It has metallic luster and is easy to oxidize when exposed to air, so it must be sealed.

Last Update：2022-10-16 17:41:59

Praseodymium - Nature

resistivity (resistivity)	68 μΩ-cm, 20°C
Exposure Limits	ACGIH: TWA 2 ppm; STEL 4 ppm OSHA: TWA 2 ppm(5 mg/m3) NIOSH: IDLH 25 ppm; TWA 2 ppm(5 mg/m3); STEL 4 ppm(10 mg/m3)
EPA chemical information	Praseodymium (7440-10-0)

Last Update：2024-04-10 22:29:15

Praseodymium - Uses and synthesis methods

Introduction

Praseodymium is a metal element located in group IIIB of the periodic table with atomic number 59, one of the rare earth elements of lanthanide, aw 140.9077, valence = 3,4. There are no stable isotopes. A soft, malleable silver metal element that defines lanthanide metals. It appears in combination with other lanthanides. The only naturally occurring isotope is 141, which is not radioactive. Fourteen radioactive isotopes were produced, however. It is used for mixed metals, rare earth metals contain 5% praseodymium, used for lighters. Another rare earth mixture containing praseodymium 30% is used as a catalyst for cracking crude oil.

Discovery history

The name of praseodymium is Praseodymium derived from the Greek words prasios (green) and didymos (paired). In 1841, the Swedish chemist Carl Gustav Mosander who discovered lanthanum separated a rare didymium soil from lanthanum-containing minerals. In 1874, the Swedish geologist Bo Theodor Clive confirmed that didymium soil is actually a mixture of two elements. In 1879, Lekau de Bouabadlan separated a new element samarium from the didymium soil obtained from the niobium-yttrium ore (samarskite), hence the name Samarium. About 40 years later, in 1885, when the steam lamp gauze was invented, Austrian Wellsbach successfully separated two elements from "praseodymium and neodymium", one named "neodymium" and the other named "praseodymium". This kind of "twins" is separated, and the praseodymium element also has a vast world to display its talents. Praseodymium is a large amount of rare earth elements, which are used in glass, ceramics and magnetic materials.

Source

Praseodymium appears in the earth's crust with an average concentration of 8 parts per million. Praseodymium is ubiquitous in the carbonate in the mineral fluorocarbon cerite. China and the United States account for the largest proportion of rare earth resources in the world. Among the economic deposits, the second largest host of neodymium is the mineral monazite, which is the main host mineral of Yangibana. Monazite deposits occur in ancient placers such as Australia, Brazil, China, India, Malaysia, South Africa, Sri Lanka, Thailand and the United States, as well as recent placers, sedimentary deposits, veins, pegmatites, carbonate rocks and alkaline complexes. Chloropite in the LREE mineral is recovered from a large alkaline igneous rock in Russia.

application

(1) praseodymium is widely used in architectural ceramics and daily ceramics. it is mixed with ceramic glaze to make color glaze, or it can be used as underglaze pigment alone. the pigment made is light yellow, pure and elegant.

(2) Used to make permanent magnets. Using cheap praseodymium-neodymium metal instead of pure neodymium metal to make permanent magnet materials, its antioxidant properties and mechanical properties are significantly improved, and it can be processed into magnets of various shapes. Widely used in various electronic devices and motors.

(3) for catalytic cracking of petroleum. The preparation of petroleum cracking catalyst in the form of praseodymium and neodymium enrichment into Y-type zeolite molecular sieve can improve the activity, selectivity and stability of the catalyst. China began to put into industrial use in the 1970s, and the amount of use is increasing.

(4) praseodymium can also be used for abrasive polishing. In addition, praseodymium is more and more widely used in the field of optical fiber.

Preparation

praseodymium chloride molten salt electrolysis method to produce praseodymium metal: PrCI3 is used as raw material, and industrial pure KC1 is prepared into a two-element electrolyte (PrCI3 ~ KC1) system according to the composition ratio, then it is put into a circular graphite electrolytic cell for melting, then direct current is introduced to carry out normal molten salt electrolysis, and PrCI3 material shall be added regularly and quantitatively. During the electrolysis process, liquid metal praseodymium precipitated at the cathode flows into the porcelain crucible, and the metal is taken out regularly for ingot casting. Chlorine gas escapes from the anode and must be treated properly before it can be discharged to protect the environment.

Hazard

If the praseodymium becomes wet or immersed in water, the released hydrogen may explode. Must be kept dry and away from the atmosphere.

Production method

The main minerals are monazite and fluorocarbon cerium lanthanum. Reduction of anhydrous chloride or fluoride with calcium can produce metallic praseodymium.

1.70g PrCl3 and 18  5g Ca are thoroughly mixed and shaken under inert atmosphere and loaded into a tantalum crucible or pressed into a cylinder by a motor press and put into a tantalum crucible. the crucible is equipped with a perforated tantalum cover for ventilation and placed in a closed MgO crucible (d = 0.0508m,h = 0.1778m). Then put it into the quartz tube (d = 0.05715m), one end of the tube is fused and sealed, and the other end is polished and embedded in the 55/50 tapered joint. The quartz tube was sealed in a vacuum system with paraffin wax. Ar is filled (purified by superheated uranium metal first) to P = 101.325kPa, and heated to 550~600 ℃ in a 6kW induction furnace to make the reaction occur (according to the sudden rise of tantalum crucible temperature). After 5min, it reached 1000 ℃ and maintained for 13min to completely agglomerate the rare earth metals produced. Cool to room temperature, soak the tantalum crucible with water to remove CaCl2 and Ca, and the rare earth metal melt remains at the bottom (1% ~ 3

Last Update：2024-04-10 22:29:15