가. 채광도급계약 체결 《갱내채광 도급 계약서》 제3조 (계약기간) 1) 계약기간은 2013년 5월 1일부터 2014년 4월 30일(1년간)까지로 한다. 2) 계약기간 만료되기 1개월 이전에 피고 회사 또는 원고의 별도의 의사표시가 없을 때에는 계약 연장에 합의한 것으로 간주하고 자동으로 1년간씩 연장한다.

§ 4(1) As of the end of each month, the number of tallytons of the Defendant Company shall be 20,000 tons up to 20,000 tons and 2) the number of tallytons exceeding 20,000 tons shall be adjusted later.

3) The end of each month shall be examined by attending and examining the Defendant Company and the Plaintiff as of the end of each month, and shall be calculated by 500,000/m, and the unit price of contract may be adjusted by mutual agreement between the Defendant Company and the Plaintiff, depending on the circumstances, even during the contract period. The payment of the price under Article 5 (Payment) (1) shall be the amount calculated by multiplying the production inspection quantity or digging performance by the contract unit price, and the payment date shall be the 20th of the following month.

On April 24, 2013, the Plaintiff entered into a mining contract under which the Defendant Company and the Plaintiff would collect and supply tin in the mine of the Defendant Company (hereinafter “instant contract”).

The contents of the instant contract relating to the instant case are as follows.

B. On January 29, 2014, the Plaintiff agreed to change the contract price between the Defendant Company and the contract price into KRW 4,044/metric tons (in cases where the monthly collection volume exceeds 30,000 tons, KRW 3,628/metric tons), and the digging rate to KRW 400,000/m.

However, on January 2014, when the amendment agreement was reached, the unit cost of each contract shall be KRW 5,000/ton, and the part exceeding 20,000 tons shall be KRW 3,628/metric tons.

C. In accordance with the instant contract from May 1, 2013 to June 30, 2014, the Plaintiff, who paid part of the amount of mining and payment, shall mine pits in the mine of the Defendant Company, collect tin and gather tin from the Defendant Company.