Earth & Environmental Sciences
battery
91%
nickel
46%
rare earth element
44%
recycling
35%
sulfate
31%
metal
29%
primary production
21%
hydrolysis
20%
sulfuric acid
18%
experimental study
17%
sodium
16%
ion
15%
oxidation
14%
leaching
11%
hydroxide
10%
salt
10%
consumption
10%
sieving
8%
separator
8%
acid
7%
agglomeration
7%
organic compound
6%
experiment
5%
plastic
5%
waste collection
5%
fiber
5%
plant production
5%
particle size
5%
Engineering & Materials Science
Nickel metal hydride batteries
100%
Recycling
44%
Sodium sulfate
32%
Rare earth elements
31%
Solvent extraction
31%
Flowcharting
29%
Ions
22%
Sieves
19%
Sulfuric acid
18%
Leaching
18%
Sodium hydroxide
17%
Recovery
15%
Salts
13%
Organic compounds
10%
Reagents
9%
Nickel
8%
Separators
8%
Metals
7%
Impurities
7%
Particle size
7%
Design of experiments
6%
Acids
6%
Agglomeration
6%
Phosphoric acid
6%
Plastics
5%
Fibers
5%
Chemical Compounds
Recycling
40%
Lanthanoid Atom
28%
Sodium Sulfate
25%
pH Value
18%
Ion
17%
Chemical Element
17%
Fiber
14%
Leaching
13%
Metal
13%
Sulfuric Acid
12%
Acid
7%
Phosphoric Acid
7%
Hydroxide
6%
Toxic
5%