Abstarct: In this study, after sampling and preparation, preliminary studies were carried out on the sample. The results showed that the lead content in the sample was about 6.5%. Initially, flotation experiments were performed on the representative sample to determine the most effective parameters on flotation. In order to do this, the effect of frother dosage, sodium sulfide dosage, potassium amyl xanthate, sodium isobutyl xanthate and sodium isopropyl xanthate as collectors, collector dosage, grinding time, solid content, pH, aeration during conditioning, conditioning time, de-sliming, re-grinding, scavenger and adding collector in two steps, were investigated. The results of the initial experiments showed that pH, particle size, solid content, sodium sulfide dosage, collector dosage and collector type were the most effective parameters, so flotation kinetics tests were designed by these parameters and optimization was performed using response surface methodology baxsed on central composite method. According to test results, the most suitable model and its parameters were selected from about 140 models. It should be noted that the frothing in flotation kinetics experiments was carried out automatically to increase the accuracy and uniformity of the flotation experiments. After the kinetics experiments, the results were compared between the laboratory results and the models. The results showed that among the models with unit kinetics constant, the overall equation was the best model. The flotation kinetics order was 1.87 which is referred to as pseudo-second order. A mathematical model was also proposed for the relation between the kinetic constant and the flotation order. The result showed that flotation order can obtain from kinetics constant as Logarithmic model (n= -0.214 Ln (k)+1.0343). Finally, the results showed that during the flotation time, the kinetics constant decreases and the flotation order increases and the relationship between the flotation order and kinetics constant versus time and recovery is presented as a mathematical model. Also the result showed that flotation order was more sensitive on recovery than kinetics constant. Overall, the three-part flotation model (with seven parameters), with fast, medium, and slow kinetics constants, was most related to the experimental results (R2 > 0.99). The relationship between model parameters and flotation operating parameters was investigated and introduced as a mathematical model. The presented models showed good correlation with the experimental data (R2 > 0.8). The optimal conditions for cruciate flotation were as follows: pH = 9, d80= 53 microns, solid content of 26%, sodium sulfide dosage 4000 g/t and 1500 g/t of PAX as a collector. By examining the effects of flotation parameters on model parameters, the results showed that the most effective parameter on k1 is the particle size, the solid content have the least effect on k2. The most effective parameters on k3 were pH and particle size and the most effective parameter on R∞ are the sodium sulfide dosage and pH.