合式한 Cu₂S의 組成은 X-ray回析로서 Cu_(1.96)S임을 確認하고 D.T.A.로써 150cc/min 3℃/min條件으로 昇溫焙燒한 結果 吸熱 및 發熱反應을 나타내는 溫度附近에서의 反應은 다음과 같은 焙燒反應이 일어남을 究明했다. ① 330℃附近; 發熱反應(第一peak) 5Cu_(1.96)S+1/5O₂→Cu_9S_5+2/5Cu₂O ② 390℃附近; 發熱反應(第二peak) Cu₂S+3/2O₂→Cu₃O+SO₂ ③ 470℃附近; 吸熱反應(第3eak) 3Cu₂S+6CuSO₄→6Cu₂O+9SO₂ ④ 490℃附近; 發熱反應(第4peak) Cu_9S_5+29/4O₂→9/2Cu₂O+5SO₂ ⑤ 650℃附近; 發熱反應(第5peak) Cu₂O+SO₂+O₂→CuO, CuSO₄ ⑥ 750℃附近; 吸熱反應(第6peak) CuSO₄→Cuo, CuSO₄+SO₃ ⑦ 780℃附近; 吸熱反應(第7peak) CuO, CuSO₄→2CuO+SO₃

Roasting mechanism of synthetic chalcocite (Cu_(1.96)S) was studied by means of D. T. A, under the conditions of the flow rate of air, 150cc/min, and the rate of temperature increment, 3℃/min. The reaction mechanisms of the exathermic and endothermic reactions in the range from 330℃ to 780℃ may be given as the followings: ① at 330℃: Exo. reaction(1st peak) 5Cu_(1.96)S+1/5O₂→Cu_9S_5+2/5Cu₂O ② at 390℃: Exo. reaction(2nd peak) Cu₂S+3/2O₂→Cu₃O+SO₂ ③ at 470℃: Endo. reaction(3rd peak) 3Cu₂S+6CuSO₄→6Cu₂O+9SO₂ ④ at 490℃: Exo. reaction(4th peak) Cu_9S_5+29/4O₂→9/2Cu₂O+5SO₂ ⑤ at 650℃: Exo. reaction(5th peak) Cu₂O+SO₂+O₂→CuO, CuSO₄ ⑥ at 750℃: Endo. reaction(6th peak) CuSO₄→Cuo, CuSO₄+SO₃ ⑦ at 780℃: Endo. reaction(7th peak) CuO, CuSO₄→2CuO+SO₃