The accumulating salt crystals have to be removed and can be both a valuable by-product and a maintenance expense.

This includes removing fibre and protein (which can be valuable by-products, for example wheat or maize gluten).

In these systems the haulm (dried stalks) of cowpea is a valuable by-product, used as animal feed.

On occasions one can buy cow, horse, poultry, or pig manure from neighbouring farms or stables, but few farmers can now afford to part with such valuable by-products.

Being sharp, crystalline, and even in quality, it was a valuable by-product, finding a ready sale for building purposes, railway sand-boxes, and various industrial uses.

First, it extracts valuable by-products; second, it renders natural gas fit to be transported to a point for commercial sale and consumption.

Nechalacho is also enriched in tantalum, niobium, zirconium, which all represent potential valuable by-products.

During the cracking process, the cadmium sulphide will be reduced to its pure metallic, non-toxic form, and will be a valuable by-product, reducing the costs of refining.

The very pure and finely divided precipitate of calcium carbonate that is generated is a valuable by-product used in the manufacture of toothpaste.

If the poor boy had been successful, what a valuable by-product might have resulted for the whole world.