Is there a name for this kind of noun (example: sand, water, salt)?

Those are called non count or mass nouns You can say how much sand or water there is: a lot of sand, a pound of sand, gallons of water, too much water. You just can't say how *many.* That is another feature of noncount nouns: they use "much": much coffee, much meat, much beer. Countable nouns use "many": many chairs, many cokes, many hamburgers.