Mineral flotation in water study. A high concentration of calcium and gypsum in water can affect the water quality and limit mineral flotation. In Minerals Engineering

(Vol. 46–47, 2013), chemical and materials engineers published a study of the impact of calcium and gypsum on the flotation properties of silica in water. Solutions of deionized water were prepared both with and without calcium/

gypsum, and the level of flotation of silica in the solution was measured using a variable called zeta potential (measured in millivolts, mV). Assume that 50 specimens for each type of liquid solution were prepared and tested for zeta potential. The data (simulated, based on information provided in the journal article) are provided in the table.

Create side-by-side graphs to compare the zeta potential distributions for the two types of solutions. How does the addition of calcium/gypsum to the solution affect water quality (measured by zeta potential of silica)?

Without calcium/gypsum -47.1 -53.0 -50.8 -54.4 -57.4 -49.2 -51.5 -50.2 -46.4 -49.7 -53.8 -53.8 -53.5 -52.2 -49.9 -51.8 -53.7 -54.8 -54.5 -53.3 -50.6 -52.9 -51.2 -54.5 -49.7 -50.2 -53.2 -52.9 -52.8 -52.1 -50.2 -50.8 -56.1 -51.0 -55.6 -50.3 -57.6 -50.1 -54.2 -50.7 -55.7 -55.0 -47.4 -47.5 -52.8 -50.6 -55.6 -53.2 -52.3 -45.7 With calcium/gypsum -9.2 -11.6 -10.6 -8.0 -10.9 -10.0 -11.0 -10.7 -13.1 -11.5 -11.3 -9.9 -11.8 -12.6 -8.9 -13.1 -10.7 -12.1 -11.2 -10.9 -9.1 -12.1 -6.8 -11.5 -10.4 -11.5 -12.1 -11.3 -10.7 -12.4 -11.5 -11.0 -7.1 -12.4 -11.4 -9.9 -8.6 -13.6 -10.1 -11.3 -13.0 -11.9 -8.6 -11.3 -13.0 -12.2 -11.3 -10.5 -8.8 -13.4