Statistical Evaluation and Optimization of Factors Affecting the Leaching Performance of Copper Flotation Waste

Table 5

Estimated effects and coefficients for concentration of leached copper.

Term	Effect	Coef.	SE Coef.	𝑇	𝑃
Constant		184.99	3.084	59.99	0.000
pH	−55.35	−27.67	3.084	−8.97	0.000
Stirring time	23.65	11.83	3.084	3.83	0.003
Temperature	14.95	7.47	3.084	2.42	0.036
pH*stirring time	10.33	5.16	3.084	1.67	0.125
pH*temperature	20.52	10.26	3.084	3.33	0.008
Stirring time*temperature	36.57	18.29	3.084	5.93	0.000
pH*stirring time*temperature	12.15	6.07	3.084	1.97	0.077
Ct Pt		−33.65	7.761	−4.34	0.001

𝑆 = 12.3351, PRESS = 6057.65, 𝑅-Sq = 94.53%, 𝑅-Sq (pred) = 78.23%, and 𝑅-Sq (adj) = 90.16%.