I bet sourcing all that sand will be a bigger problem than they expect as sand is a rare and nonrenewable resource that's heavily in demand for concrete and sourcing it has all sorts of environmental issues of its own.
They should look into replacing that with something that's also cheap waste. Maybe crushed glass would work?
glass is made from sand,
there is less glass in world then sand,
and again,
why lock more precious commodity in another product
which we are already making from other less precious commodity ?
It's the shape of the grains of sand that's bad for concrete, not the chemical composition. It gets less angular and more round when it moves in the desert and it doesn't bound well with cement. Sand that is good for concrete is rare and making it is expensive. The "bad" sand that is common everywhere is still perfect to make glass.
twenty-five percent of Africa is literally covered in sand. Sand comes in different granularity and compositions, but for concrete this is often irrelevant.
Actually it matters quite a bit. That's why countries which are literally filled with desert sand import river/sea sand for their construction. Finding a way to make desert sand usable for construction concrete would be significant.
They should look into replacing that with something that's also cheap waste. Maybe crushed glass would work?