Poldice Mine was active in 17th century, which makes it one of the earliest record in Cornwall. Poldice Mine produced over 150,000 tons copper ore, 1,500 tons tin and 2,500 tons arsenic.
A dispute is recorded in 1678, over a water-course, had not been settled by 1681, when a petition before the Lord Warden of the Stannaries stated that the mine had produced £1,200 per year for Henry VIII.
In 1685 the mine was described by Hals as "that unparalleled and inexhaustible tin work which for about forty years space hath employed from eight hundred to a thousand men and boys labouring for tin....where they have produced for that time, yearly, at least £20,000 worth of that commodity. "
However by 1726 it is written off as "once profitable but now wrought so deep that there is no great benefit to be expected".
1742 William Lemon of Poldice successfully campaigned in Parliament to have the duty on sea borne coal dropped. The cessation of this duty in 1741 made it viable to purchase steam pumping engines and almost immediately 5 steam engines were purchased. Cornwall, of course, had no coal of its own, and needed to import coal by sea for all steam engines in its mines. William Lemon was the principal adventurer and provided the capital needed to solve the mine's water problem.
1748 The mine was in the vanguard of the construction of The County Adit. It was the brainchild of John Williams of Scorrier, then manager of Poldice, who needed to find a way to drain the maine. From its discharge near Point Mills in the Carnon Valley, The County Adit reached Poldice in the late 1760s, by which time the mine was over 100 fathoms deep in places. Deep adit construction played a vital role in removing water from Cornish mines and at its peak, the County Adit drained an estimated 13 million gallons/day from over 40 mines around Redruth and St Day through 38 miles of adits. John Williams is noted for driving the County Adit from Bissoe Bridge to drain the mines of Poldice, it took twenty years and the completed work takes in numerous branch adits and drains fifty mines. After profiting spectacularly from a sudden tin price rise, John Williams built Scorrier House, enlarging it substantially in 1845.
1778. Two Newcomen engines, of 66-inch and 60-inch cylinders, were bought to raise water to the adit. These engines consumed 192 bushels of coal per day, at a cost of £9. These were replaced almost immediately by two 63-inch Bolton and Watt engines, with a second pair in 1787.
1787 copper sales amounted to £11,315, compared with tin sales of £9,868. In 1748 the mine had produced tin only.
1787 saw riots at Poldice mine owing to copper price falls.
1792 the mine produced 575 tons of copper ore in two months, sales for 1792-98 inclusive amounting to £151,471.
1793 Bolton and Watt refused, on account of the money owed them by the mine, to deliver a 66-inch double (compound) engine on the mine. Odd in as much as the mine looked to be profitable at that time.
1800-04 Poldice was amalgamated with Wheal Unity. In these years 41,196 tons of copper ore were raised, and sold for £392,676, realising a profit (including £6,780 for tin sales) of £45,441. However, despite this output the mine was only 20 fathoms deeper in 1821 than it had been 60 years earlier.
1819 the first railway in Cornwall. The Gwennap mines were a long way from both the north and south coasts, and as a result incurred high costs to transport timber, coal and ore. John Williams of Scorrier constructed a horse-drawn plateway from his mines at Poldice through Scorrier to a newly-constructed harbour on the north coast at Portreath.
1852 Poldice was amalgamated with Carharrack Mine and Wheal Maid and worked as St Day United. In 1864 Wheals Unity, Gorland, Creegbrawse and Penkevil were added to the sett and the name was changed to Poldice United. The workings were 194 fathoms below adit (54 fathoms) by this time and 553 people were employed. Nine engines worked in the mines, from an 85-inch pumping engine to an 18-inch winder. During this period tin output increased, and became greater than that of copper in 1869.
By 1870 the sett was known as Poldice Mines, was 210 fathoms deep and employed 400 people.
1873 Poldice lost £1,862 during the first three months. In May it was decided to persevere for one more month, the decision being that of Sir F. M. Williams who held 1,700 of the 2,000 shares. Tin prices were falling and they decided to abandon the sett in June. Problems had been experienced with pumping and with chokes in the County Adit, a new 85" engine having been installed in January 1873.
1889 The mine as it was abandoned again. But the dumps were worked.
1890 over 5,100 tons of tin stone was sold, taken from the waste tips of Poldice and other Gwennap mines (Unity, Gorland and Goongumpus).
1905-6 a small amount of ore was produced working with Wheals Cusgarne and Buller. Closed 1913.
1926 the sett was acquired by Park-an-Chy Mine for its ore dressing plant. The mill was completed in early 1928 and equipped with 12 heads of Fraser and Chalmers stamps modified from the Nissen design. Other equipment included Hardinge Mills, Fraser and Chalmers shaking tables, Wetherill magnetic separators and hydraulic classifiers. Two Brunton calciners were used, parts of the old flues having been overhauled. Froth flotation also appears to have been carried out on the mine. The mill had a capacity of 120 tons per day. 100 tons of ore produced 4 tons of concentrate. The concentrate averaged 20% Sn, 35% As2O3, 5% WO3 and 0.5% Cu.
1928 Underground activity had recommenced by this time, in the hope of supplementing ore from Park-an-Chy, and the main shaft was cleared down to the 505 foot level by September 1928.
1930 operations at both mines ceased, probably because of a lack of ore reserves, although mining was stated to have been two years ahead of the mill when it started work.
1932 The mill was finally dismantled.
Today there are extensive area of dumps around prominent remains of calciner, chimney and buddles.
Gwennap Area Mines.