New insights into selective-depression mechanism of novel depressant EDTMPS on magnesite and quartz surfaces: Adsorption mechanism, DFT calculations, and adsorption model

•EDTMPS and DDA is more selective compared to DDA alone.•EDTMPS has a selective-depression effect on magnesite flotation.•EDTMPS onto magnesite could be attributed to selective chelation on Mg.•The interaction between DDA and magnesite was weakened by the pre-adsorption of EDTMPS.