The Hamaker constant is a key parameter for characterization of Van der Waals force between charged colloidal particles and is also of significance to studying the stability of magnesium hydroxide in desulfurization wastewater.In this study

the Hamaker constant of spherical magnesium hydroxide colloid in symmetric electrolyte solution was derived based on the DLVO theory.The results show that

the Hamaker constant is closely related to the surface potential parameter v_0

antiionic valence z and critical coagulation concentration c_(ccc )of the spherical magnesium hydroxide colloid.The dynamic light scattering technology was applied to investigate the coagulation process of the magnesium hydroxide

and the critical coagulation concentration c_(ccc) of the sodium chloride solution was calculated as 47.28 mmol/L.Meanwhile

based on the Gouy-Chapman equation of potential distribution

expression of the surface potential parameter v_0 of the magnesium hydroxide was derived

and its calculated value was 0.357.Furthermore

the Hamaker constant of the magnesium hydroxide in sodium chloride solution was calculated as 7.99×10~(-20) J.