Tin and copper in Cornish mines, was the main driver early on.
That isn't really the point, yes it was the 'age of steam' but in reality it made a few marginal mines profitable. There were no steam trains, no steam ships, no wide spread mechanisation.
Britain wasn't some backwater that was propelled ahead of spain due to accidentally discovering steam power. It was already a power in it own right, with trading networks and markets for these raw materials, that was the impetus for the development of steam.
Coal mining was a thosand times greater than metal mining by the late 18th / early 19th century:
Coal was so abundant in Britain that the supply could be stepped up to meet the rapidly rising demand. About 1770-1780 the annual output of coal was some 6.25 million long tons.
Versus:
Despite the collapse of the copper mining industry in 1866, the tin industry was still riding high producing 10,000 tons of tin a year - about half the world's production.
"Newcomen's great achievement was his steam engine, developed around 1712; combining the ideas of Thomas Savery and Denis Papin, he created a steam engine for the purpose of lifting water out of a tin mine." [1]
Plus that's 700,000 tons of copper, copper ore typically contains 2%? Copper, so your 700,000 tons of copper represents 35 million tons of ore. I'm undecided whether relative weight is even a good comparator. Sure value of output would be the best comparison?
You seem to be referencing Savery engines that weren't successful, whereas I'm referencing Newcomen engines that were. Can we agree that unsuccessful engines weren't a factor in Britain overtaking Spain?
My point is and remains that when England leapt ahead of Spain, one primary driver was a tremendous increase in availability of primary energy. Coal replaced other scarce fuels, largely wood and charcoal, rare in both Spain and Britain, and steam engines themselves bootstrapped that process.
The immediate applications of coal may not have been yet more steam power (that waited for Watt in ~1770 and more especially expiry of his patents in 1800), but it was applied to space heat and cooking, glassmaking, and smelting of various metals, though most especially iron. It also freed up limited domestic and importe lumber for shipbuilding.
This at a time when other factors such as Spain's plunder of New World gold an silver were leading to rampant inflation and an early example of what's now called "Dutch Disease". Spain itself has comparatively little coal (mostly in the north), whilst the major industrial powers of 19th century Europe, France, Germany, Austria-Hungary, all had major domestic coal deposits, crucially: located near coasts or rivers. At a time when cargo moved almost exclusively by water, this was absolutely essential.
By comparison, in the US, despite vastly greater coal deposits, wood (generally locally available) remained the primary fuel until the development of railroads (and high-strength steel rather than iron rails, to handle heavily loaded coal cars without splitting, also dependant on coked coal fuel), in the 1880s.
For further references, see Vaclav Smil (Energy in World History, Energy and Civilization, also Making the modern world : materials and dematerialization, on material use), Manfred Weissenbacher (Sources of Power), and Gregory Clark (A Farewell to Alms).
Regards copper ores: as of the 18th century, English copper mines averaged 12% concentration, with high-yield mine typically higher. It's modern ores which are of far lower concentration (though 2% would now be considered high). So cut your overburden estimates by a factor of at least six. And yes, mining costs increase directly with the inverse of ore grade. That overburden doesn't move itself.
The references I'm familiar with all hugely emphasise the use of steam-driven pumps in coal mining, particularly for coastal and subsea coal mines. Though other applications existed. And quantities of energy resource mining tend to be prodigious relative to materials mining. Only water exceeds present-day energy minerals in quantity, followed by rock, sand, and gravel (Smil, Making).
"When Philip IV succeeded his father in 1621, Spain was clearly in economic and political decline, a source of consternation."
"The Spain that the sickly young Charles II (1661-1700) inherited was clearly in decline and there were more losses immediately." [1]
These are both from before the steam engine was invented. I don't think its reasonable blame steam power for the downfall of Spain. The dates just don't really line up, especially not when you look when steam became a major driving force.
Now I agree with your point that the availability of coal was a huge factor in the industrial revolution.
Ps looking up copper ore concentrations, I got the same 12% figure, I thought it questionable as its so far higher than other concentrations. Apparently modern ore has 0.6% copper.
There are, of course, multiple factors. And Spain was in decine, for multiple reasons, as the Industrial Revolution was starting to cook off in the 18th century -- whether you put the start date at the beginning, middle, or end of that period doen't much matter: Spain missed the starting gun, and never really got back in the game until the 20th century.
As to what country took title -- I'd have to check an authoritative source, possibly Maddison's data if it has sufficient granularity, but my money would be on France or the Netherlands, rather than England, at least through about 1755 (Seven Years War).
And by the 19th century, it was previously unorganised states such as Germany who'd utterly surpassed Spain, whilst the (now United) Britain benefitted hugely by avoiding the revolutions and wars that wracked Europe through 1848 (and somewhat beyond), as well as control of India (providing saltpetre for gunpowder) and China (general trade, once the Brits discovered the balance-of-trade leveling properties of opium), Canada, and Australia.
Even modest shifting of fuels away from wood gave compelling advantages. Smil credits Dutch use of peat for prt of that nation's success. Transport systems, ag productivity, attitudes toward invention and discovery (Catholic Spain vs Anglican England & Protestant Holland), canal building, political divisions, domestic resource access, colonial access, etc., etc., all played roles.
But after 1800, ability to access an utilise fossil fuels came to dominate, frequently a self-reinforcing process.
Smil, Weissenbacher, et al, make for fascinating reading (see previous).
