As easy surface resources and minerals were used up quickly, mankind had to resort to digging in the earth to acquire important things like gold, silver, possibly iron? In this day and age, we have a super high concern for safety and reliability, especially when it comes with high risk environments such as mines or manufacturing or oil rigs. Using modern science we understand things like:
That air in a mine can be dangerous, and why ventilation is needed, what effects could be seen from large miner population in a cramped mineshaft could have
The presence of poisonous gas pockets and their effects (sudden death?!) How might this be seen in more simple eyes?
Another air-related question would be lighting. My idea of lighting in a mine is a torch, which is another air-consuming item, and also produces hazardous smoke, were there other lighting methods and did people understand that torches were dangerous (especially possibly igniting said gas pockets in the above question)
How much reinforcing (if any) is needed for mineshafts and the idea of structural loads
How to find minerals we need (in modern days, we have a superior understanding of geology and natural processes which can give us a good idea of where certain things ought to be), without such modern tools how did people find what they needed?
Where labor came from for miners, and what care was extended to them
Lastly, what major improvements to mining processes that affect the above (or even just tangentially related to mining) were created, and possibly what led to the improvement's need to be invented?
For people without modern technology, a lot of the above seems like it would be unknown as far as I can see. What historical accounts or stories or information exist as far as things like these? Looking for answers that can span prehistory to the near-modern era.
Me! Me! I'll take a stab at mining methods in the mid-1800s!
The discovery of ore bodies - prospecting - happened primarily by someone finding fragments of ores and/or examining the faces of different gullies and ravines, and erosion patterns on the ground. From these facts it was possible to construct a map that, with luck, might point to a possible location of the "mother" lode. Once the location was narrowed down, a series of test shafts or "pits" were dug or "sunk" to ascertain whether the ground really held a mineral vein or not. In the "shoading" method, the general direction of the lode(s) was first ascertained, and a series of paired pits were sunk at regular distances as nearly at right angles as possible to the assumed run of the veins, on both sides of the assumed run of the vein. These pits were typically about three by six feet in size, i.e. just large enough for one working man. Then the pits were connected to their pairs by so-called galleries (tunnels) so that they would connect with the vein if it existed.
If sufficient quantities of good ore were to be found, the pits would be expanded to proper shafts and galleries to proper levels to enable mining.
Obviously, this method was somewhat of a hit or miss, and required quite a bit of labour. Labour was often cheap, though. Nevertheless, core drills were obviously a welcome invention, but these did not come into general use until late 1800s, and not even then universally. I know for a fact that pits were dug as late as in 1914 in Finland, as drills of the day could not penetrate very deep into rock.
A major problem in any mine before the invention of steam pumps was water seeping in. Water was kept at bay by various types of pumps, and large amounts of water seeping in required drainage excavations, i.e. "ditches" where the water collected and could be pumped out. The preferred method, if the geography allowed, was to drive an "adit" tunnel from the mine to adjoining valley. This would have served as a natural drainage channel, and was also greatly beneficial for hauling material from the mine: instead of having to lift the ore, mining carts could be pushed down an incline.
It is difficult to generalize how much reinforcing the shafts, levels and adits required, since this depended on the rock in question. It was also very rare if not unheard of that anyone actually calculated the loads the reinforcing would need to bear. However, the rule of thumb was that reinforcing timbers would be about 8 x 8 inches for the heaviest kind of timbering, for the most cases 6 x 6, and "very seldom" 5 x 5. These were worked into timber frames, which were often simply placed next to each other; in cases where fewer frames were used, the frames were to be "never set farther than three feet apart, and if the facing boards [placed between the frames] are not very strong, say 2 or 3 inch planks, the distance is 2 feet and less."
Another rule of thumb was that limestone was never to be trusted and required much timber to secure; beyond that, it was a matter of mine superintendent's and foreman's judgement.
For ventilation, it was agreed that at least two shafts were necessary. To expedite ventilation, more shafts and more levels were dug. A plan of Huel Crofty copper mine in Cornwall shows that levels are dug ten fathoms (16-18 m) from each other, "since by this arrangement the ventilation of the workings is [...] well maintained." This was the common practice in the UK at least. By mid-1800s, canvas tubes 12 inch diameter, supported by metal hoops and suspended overhead, could be used to force additional air some 200 to 300 yards; for one-man use, smaller 3-inch tubes were also used.
Of course, air inside the mines was never quite wholesome by our standards, and miners led short lives. Lung diseases were common, and of other diseases, one particularly interesting was nystagmus. Miners were often forced to work in tight spaces lying on their side, aiming their picks accurately to upwards and slightly to one side. This required straining the eyes to an unnatural position. When repeated for years in low light conditions, the eyes would permanently "twitch" to one side, and could result to permanent disability.
Particularly in coal mines, the presence of explosive methane, coal dust, or carbon monoxide was a serious threat. The dangers of open flame were well understood, but there were few options: dried fish skins (which give out a bit of bioluminescence) and bottled fireflies were used, but these provided at best rudimentary lighting. A contraption known as Spedding mill was also used from 1750s: a boy would work the handle of one of these mills, rotating a steel disk against a flint and producing sparks. It was believed these sparks could not ignite explosions, a notion that was eventually proven to be false. The threat of explosions was somewhat diminished after the introduction of safety lamps by George Stevenson and Sir Humphry Daly after 1816 - these isolated the flame behind a veil of gauze or glass channels with small enough holes so that the flame could not pass - but serious accidents happened nevertheless. The downside was increased incidence of nystagmus, since safety lamps gave less light.
A textbook from 1854 [1] noted, however, that the goal should be to provide enough fresh air so that open fire and candles could be used, but it seems unlikely that this was the case in most mines where it was most needed.
The miners did not have a thorough understanding of dangerous gases of course, and different "bad airs" were referred as "damps" (after German dampf, vapour). "Firedamp," for example, was any explosive mixture; "blackdamp," nitrogen or carbon dioxide without oxygen; "whitedamp," resulting from incomplete combustion of coal and with potentially suffocating or explosive concentration of carbon monoxide; "stinkdamp" of noxious gases, primarily hydrogen sulfide; and "afterdamp," anything potentially poisonous, suffocating, or explosive remnant that followed explosions. Canaries and other birds were famously used to warn miners of dangerous concentrations of suffocating gases, but other methods for evading these dangers included the "fireman:" someone took a candle attached to a long pole and probed the tunnels, dropping down if an explosion occurred (and, if he survived, immediately rising up afterwards to escape the resulting afterdamp). The color of the flame might give them some warning of dangerous concentrations, but this was far from foolproof method, as you may imagine.
Hope this helps some! For labour issues, someone better qualified may give better answers :).
All quotes from the main source I used:
[1] Phillips, J. A. (1854). A manual of metallurgy, or practical treatise on the chemistry of the metals. (2nd ed.). London and Glasgow: R. Griffin and Company. Available from http://hdl.handle.net/2027/uc2.ark:/13960/t7mp4x631?urlappend=%3Bseq=376
You have excellently clarified your original question with some more specific ones, but you might attract more, and better, answers if you specify a narrower time period or location. Did you have any in mind?
hi, there have been a few posts on mining; I've rounded up a few (I've linked the FAQ, searched for "mining" and "gold rush") but there are more out there if you're up for searching other keywords.
Ancient world
How did we figure out mining, anyway? - featuring /u/itsallfolklore
Which came first, the mining pickaxe or the metal it's made with? and other ordering questions - /u/verdatum goes in-depth on ancient methods
Many civilizations, like Ancient Egypt, are famous for their gold. How was it mined, smelted down, and crafted into things like coins or art? - /u/MarcEcko discusses Ancient Egypt
Middle Ages
Gold Rush
How much did gold mining technology improve between the 16th and the late 19th century? - featuring /u/itsallfolklore
What was it like to be a Gold Miner in the mid to late 1800's working in the California Desert? - featuring /u/Artw and /u/itsallfolklore
Were there safety features for workers in the California Gold Rush? - featuring /u/itsallfolklore
How much gold was actually found in California during the Gold rush? - featuring /u/itsallfolklore
Why is there no more significant gold mining in California? Was all the accessible gold mined or is there another reason? - featuring /u/Artw and /u/itsallfolklore
Why did the California Gold Rush end after only several years? - featuring /u/itsallfolklore
For the Renaissance period, two primary sources that cover your questions are:
De Re Metallica by Georgius Agricola. First edition 1556: This covers the Mining and refining of metals. it has many fantastic woodcuts with cut-away views of mining methods and machinery. It certainly covers your questions on ventilation methods (for the sixteenth century at least). The simplest one being to site your mine entrance so that the prevailing wind naturally ventilates the mine. But by the time of Agricola there were many more complex mechanical means to accommodate deeper mining.
De La Pirotechnica by Vannoccio Biringuccio. Published 1540: This book is more focused on what to do with your ore after you've mined it, but again, it contains many fantastic woodcuts of the smelting, refining and casting process of the time. I had the privilege to be part of a project to create a working reproduction of a small bronze foundry as shown in De La Pirotechnica. We had some success casting bronze bells and even a bronze cooking cauldron using his methods, though less success with a small bronze cannon.
By no means a subject that I'm well versed in but it's my understanding that in the ancient world "easy surface resources and minerals" were actually not used up all that quickly, but that people just started going further afield to look for the resources.
So there's a large number of slag deposits in incredibly in isolated areas of Oman that were part of the copper trade with Mesopotamia where they could just carry out open-pit surface mining. It's an old article but this is described a bit here: http://www.persee.fr/doc/arsci_0399-1237_1981_sup_1_1_1138
I've also visited copper slag sites in some of the deserts of Jordan with broadly similar conditions that according to a local guide were from the Roman era, though that's obviously not a reliable source.
Lastly, what major improvements to mining processes that affect the above (or even just tangentially related to mining) were created, and possibly what led to the improvement's need to be invented?
Oh boy, where to start? Disclaimer: I’m a geologist and I have been active in the canadian mining industry since the 1980’s (the sub’s rules says post-1996 is off limits, so we’re good!)
One major safety issue, as you point out, is fires. An underground fire is a terrible risk factor underground, as it will sap out the oxygen and smother the miners. Major fires in the Hollinger Mine (1949), the East Malartic mine (1947), which respectively led to the death of 39 and 16 miners led to the creation of dedicated mine rescue organisations in Ontario and Québec (Ontario Mine Rescue, Service de sauvetage minier). These train personnel and develop intervention techniques, and hold annual competitions. They have shown themselves to be quite effective in preventing loss of life, both through direct intervention, and through developing and implementing safety standards. Everybody knows the rescue team in any given mine.
One Innovation I’ve found quite effective is the deployment of silent alarms. This has been a pretty standard feature in most Canadian underground mining operation since at least the early 80’s. It addresses the need to reach all workers in a noisy environment with mandatory ear protection. A peculiar disagreeably scented compound (mercaptan) is injected in the ventilation system. When you smell the skunk-like odor, you drop what you are doing and hurry to the closest safe room and away communications.
I’m not sure if you have an interest in improvements in mining methods and techniques such as long-hole and heap leaching which revolutionised mining in the 80’s and allowed what were previously sub-economic deposits to be mined economically.