From: Zefram Date: Fri, 8 Aug 2014 22:22:36 +0000 (+0100) Subject: More manual X-Git-Url: http://81.2.79.47:8989/gitweb/?a=commitdiff_plain;h=eed803349ccd0fb0cc99ab841b7d7c9de17c48e8;p=zefram%2Fminetest%2Ftechnic.git More manual Added sections on the technic-specific kinds of item processing, and on generic metal mechanics, and the specific trickery around iron (merging in notes_on_iron). --- diff --git a/manual.md b/manual.md index 85921a2..94d2359 100644 --- a/manual.md +++ b/manual.md @@ -160,12 +160,274 @@ elevation -150 downwards. It is much harder to dig than standard stone, so impedes mining when it is encountered. It has mainly decorative use, but also appears in a couple of machine recipes. +alloying +-------- + +In technic, alloying is a way of combining items to create other items, +distinct from standard crafting. Alloying always uses inputs of exactly +two distinct types, and produces a single output. Like cooking, which +takes a single input, it is performed using a powered machine, known +generically as an "alloy furnace". An alloy furnace always has two +input slots, and it doesn't matter which way round the two ingredients +are placed in the slots. Many alloying recipes require one or both +slots to contain a stack of more than one of the ingredient item: the +quantity required of each ingredient is part of the recipe. + +As with the furnaces used for cooking, there are multiple kinds of alloy +furnace, powered in different ways. The most-used alloy furnaces are +electrically powered. There is also an alloy furnace that is powered +by directly burning fuel, just like the basic cooking furnace. Building +almost any electrical machine, including the electrically-powered alloy +furnaces, requires a machine casing component, one ingredient of which +is brass, an alloy. It is therefore necessary to use the fuel-fired +alloy furnace in the early part of the game, on the way to building +electrical machinery. + +Alloying recipes are mainly concerned with metals. These recipes +combine a base metal with some other element, most often another metal, +to produce a new metal. This is discussed in the section on metal. +There are also a few alloying recipes in which the base ingredient is +non-metallic, such as the recipe for the silicon wafer. + +grinding, extracting, and compressing +------------------------------------- + +Grinding, extracting, and compressing are three distinct, but very +similar, ways of converting one item into another. They are all quite +similar to the cooking found in the basic Minetest game. Each uses +an input consisting of a single item type, and produces a single +output. They are all performed using powered machines, respectively +known generically as a "grinder", "extractor", and "compressor". +Some compressing recipes require the input to be a stack of more than +one of the input item: the quantity required is part of the recipe. +Grinding and extracting recipes never require such a stacked input. + +There are multiple kinds of grinder, extractor, and compressor. Unlike +cooking furnaces and alloy furnaces, there are none that directly burn +fuel; they are all electrically powered. + +Grinding recipes always produce some kind of dust, loosely speaking, +as output. The most important grinding recipes are concerned with metals: +every metal lump or ingot can be ground into metal dust. Coal can also +be ground into dust, and burning the dust as fuel produces much more +energy than burning the original coal lump. There are a few other +grinding recipes that make block types from the basic Minetest game +more interconvertible: standard stone can be ground to standard sand, +desert stone to desert sand, cobblestone to gravel, and gravel to dirt. + +Extracting is a miscellaneous category, used for a small group +of processes that just don't fit nicely anywhere else. (Its name is +notably vaguer than those of the other kinds of processing.) It is used +for recipes that produce dye, mainly from flowers. (However, for those +recipes using flowers, the basic Minetest game provides parallel crafting +recipes that are easier to use and produce more dye, and those recipes +are not suppressed by technic.) Its main use is to generate rubber from +raw latex, which it does three times as efficiently as merely cooking +the latex. Extracting was also formerly used for uranium enrichment for +use as nuclear fuel, but this use has been superseded by a new enrichment +system using the centrifuge. + +Compressing recipes are mainly used to produce a few relatively advanced +artificial item types, such as the copper and carbon plates used in +advanced machine recipes. There are also a couple of compressing recipes +making natural block types more interconvertible. + +centrifuging +------------ + +Centrifuging is another way of using a machine to convert items. +Centrifuging takes an input of a single item type, and produces outputs +of two distinct types. The input may be required to be a stack of +more than one of the input item: the quantity required is part of +the recipe. Centrifuging is only performed by a single machine type, +the MV (electrically-powered) centrifuge. + +Generally, centrifuging separates the input item into constituent +substances, but it can only work when the input is reasonably fluid, +and in marginal cases it is quite destructive to item structure. +(In real life, centrifuges require their input to be mainly fluid, that +is either liquid or gas. Few items in the game are described as liquid +or gas, so the concept of the centrifuge is stretched a bit to apply to +finely-divided solids.) + +The main use of centrifuging is in uranium enrichment, where it +separates the isotopes of uranium dust that otherwise appears uniform. +Enrichment is a necessary process before uranium can be used as nuclear +fuel, and the radioactivity of uranium blocks is also affected by its +isotopic composition. + +A secondary use of centrifuging is to separate the components of +metal alloys. This can only be done using the dust form of the alloy. +It recovers both components of binary metal/metal alloys. It can't +recover the carbon from steel or cast iron. + +metal +----- + +Many of the substances important in technic are metals, and there is +a common pattern in how metals are handled. Generally, each metal can +exist in five forms: ore, lump, dust, ingot, and block. With a couple of +tricky exceptions in mods outside technic, metals are only *used* in dust, +ingot, and block forms. Metals can be readily converted between these +three forms, but can't be converted from them back to ore or lump forms. + +As in the basic Minetest game, a "lump" of metal is acquired directly by +digging ore, and will then be processed into some other form for use. +A lump is thus more akin to ore than to refined metal. (In real life, +metal ore rarely yields lumps ("nuggets") of pure metal directly. +More often the desired metal is chemically bound into the rock as an +oxide or some other compound, and the ore must be chemically processed +to yield pure metal.) + +Not all metals occur directly as ore. Generally, elemental metals (those +consisting of a single chemical element) occur as ore, and alloys (those +consisting of a mixture of multiple elements) do not. In fact, if the +fictional mithril is taken to be elemental, this pattern is currently +followed perfectly. (It is not clear in the Middle-Earth setting whether +mithril is elemental or an alloy.) This might change in the future: +in real life some alloys do occur as ore, and some elemental metals +rarely occur naturally outside such alloys. Metals that do not occur +as ore also lack the "lump" form. + +The basic Minetest game offers a single way to refine metals: cook a lump +in a furnace to produce an ingot. With technic this refinement method +still exists, but is rarely used outside the early part of the game, +because technic offers a more efficient method once some machines have +been built. The grinder, available only in electrically-powered forms, +can grind a metal lump into two piles of metal dust. Each dust pile +can then be cooked into an ingot, yielding two ingots from one lump. +This doubling of material value means that you should only cook a lump +directly when you have no choice, mainly early in the game when you +haven't yet built a grinder. + +An ingot can also be ground back to (one pile of) dust. Thus it is always +possible to convert metal between ingot and dust forms, at the expense +of some energy consumption. Nine ingots of a metal can be crafted into +a block, which can be used for building. The block can also be crafted +back to nine ingots. Thus it is possible to freely convert metal between +ingot and block forms, which is convenient to store the metal compactly. +Every metal has dust, ingot, and block forms. + +Alloying recipes in which a metal is the base ingredient, to produce a +metal alloy, always come in two forms, using the metal either as dust +or as an ingot. If the secondary ingredient is also a metal, it must +be supplied in the same form as the base ingredient. The output alloy +is also returned in the same form. For example, brass can be produced +by alloying two copper ingots with one zinc ingot to make three brass +ingots, or by alloying two piles of copper dust with one pile of zinc +dust to make three piles of brass dust. The two ways of alloying produce +equivalent results. + +iron and its alloys +------------------- + +Iron forms several important alloys. In real-life history, iron was the +second metal to be used as the base component of deliberately-constructed +alloys (the first was copper), and it was the first metal whose working +required processes of any metallurgical sophistication. The game +mechanics around iron broadly imitate the historical progression of +processes around it, rather than the less-varied modern processes. + +The two-component alloying system of iron with carbon is of huge +importance, both in the game and in real life. The basic Minetest game +doesn't distinguish between these pure iron and these alloys at all, +but technic introduces a distinction based on the carbon content, and +renames some items of the basic game accordingly. + +The iron/carbon spectrum is represented in the game by three metal +substances: wrought iron, carbon steel, and cast iron. Wrought iron +has low carbon content (less than 0.25%), resists shattering, and +is easily welded, but is relatively soft and susceptible to rusting. +In real-life history it was used for rails, gates, chains, wire, pipes, +fasteners, and other purposes. Cast iron has high carbon content +(2.1% to 4%), is especially hard, and resists corrosion, but is +relatively brittle, and difficult to work. Historically it was used +to build large structures such as bridges, and for cannons, cookware, +and engine cylinders. Carbon steel has medium carbon content (0.25% +to 2.1%), and intermediate properties: moderately hard and also tough, +somewhat resistant to corrosion. In real life it is now used for most +of the purposes previously satisfied by wrought iron and many of those +of cast iron, but has historically been especially important for its +use in swords, armour, skyscrapers, large bridges, and machines. + +In real-life history, the first form of iron to be refined was +wrought iron, which is nearly pure iron, having low carbon content. +It was produced from ore by a low-temperature furnace process (the +"bloomery") in which the ore/iron remains solid and impurities (slag) +are progressively removed by hammering ("working", hence "wrought"). +This began in the middle East, around 1800 BCE. + +Historically, the next forms of iron to be refined were those of high +carbon content. This was the result of the development of a more +sophisticated kind of furnace, the blast furnace, capable of reaching +higher temperatures. The real advantage of the blast furnace is that it +melts the metal, allowing it to be cast straight into a shape supplied by +a mould, rather than having to be gradually beaten into the desired shape. +A side effect of the blast furnace is that carbon from the furnace's fuel +is unavoidably incorporated into the metal. Normally iron is processed +twice through the blast furnace: once producing "pig iron", which has +very high carbon content and lots of impurities but lower melting point, +casting it into rough ingots, then remelting the pig iron and casting it +into the final moulds. The result is called "cast iron". Pig iron was +first produced in China around 1200 BCE, and cast iron later in the 5th +century BCE. Incidentally, the Chinese did not have the bloomery process, +so this was their first iron refining process, and, unlike the rest of +the world, their first wrought iron was made from pig iron rather than +directly from ore. + +Carbon steel, with intermediate carbon content, was developed much later, +in Europe in the 17th century CE. It required a more sophisticated +process, because the blast furnace made it extremely difficult to achieve +a controlled carbon content. Tweaks of the blast furnace would sometimes +produce an intermediate carbon content by luck, but the first processes to +reliably produce steel were based on removing almost all the carbon from +pig iron and then explicitly mixing a controlled amount of carbon back in. + +In the game, the bloomery process is represented by ordinary cooking +or grinding of an iron lump. The lump represents unprocessed ore, +and is identified only as "iron", not specifically as wrought iron. +This standard refining process produces dust or an ingot which is +specifically identified as wrought iron. Thus the standard refining +process produces the (nearly) pure metal. + +Cast iron is trickier. You might expect from the real-life notes above +that cooking an iron lump (representing ore) would produce pig iron that +can then be cooked again to produce cast iron. This is kind of the case, +but not exactly, because as already noted cooking an iron lump produces +wrought iron. The game doesn't distinguish between low-temperature +and high-temperature cooking processes: the same furnace is used not +just to cast all kinds of metal but also to cook food. So there is no +distinction between cooking processes to produce distinct wrought iron +and pig iron. But repeated cooking *is* available as a game mechanic, +and is indeed used to produce cast iron: re-cooking a wrought iron ingot +produces a cast iron ingot. So pig iron isn't represented in the game as +a distinct item; instead wrought iron stands in for pig iron in addition +to its realistic uses as wrought iron. + +Carbon steel is produced by a more regular in-game process: alloying +wrought iron with coal dust (which is essentially carbon). This bears +a fair resemblance to the historical development of carbon steel. +This alloying recipe is relatively time-consuming for the amount of +material processed, when compared against other alloying recipes, and +carbon steel is heavily used, so it is wise to alloy it in advance, +when you're not waiting for it. + +There are additional recipes that permit all three of these types of iron +to be converted into each other. Alloying carbon steel again with coal +dust produces cast iron, with its higher carbon content. Cooking carbon +steel or cast iron produces wrought iron, in an abbreviated form of the +bloomery process. + +There's one more iron alloy in the game: stainless steel. It is managed +in a completely regular manner, created by alloying carbon steel with +chromium. + subjects missing from this manual --------------------------------- This manual needs to be extended with sections on: -* alloying +* rubber * electrical networks * the powered machine types * how machines interact with tubes diff --git a/notes_on_iron b/notes_on_iron deleted file mode 100644 index 7facbcf..0000000 --- a/notes_on_iron +++ /dev/null @@ -1,68 +0,0 @@ -Notes on iron and steel -======================= - -Alloying iron with carbon is of huge importance, but in some processes -the alloying is an implicit side effect rather than the product of -explicit mixing, so it is a complex area. In the real world, there is -a huge variety of kinds of iron and steel, differing in the proportion -of carbon included and in other elements added to the mix. - -The Minetest default mod doesn't distinguish between types of iron and -steel at all. This mod introduces multiple types in order to get a bit -of complexity and flavour. - -Leaving aside explicit addition of other elements, the iron/carbon -spectrum is here represented by three substances: wrought iron, -carbon steel, and cast iron. Wrought iron has low carbon content -(less than 0.25%), resists shattering, and is easily welded, but is -relatively soft and susceptible to rusting. It was used for rails, -gates, chains, wire, pipes, fasteners, and other purposes. Cast iron -has high carbon content (2.1% to 4%), is especially hard, and resists -corrosion, but is relatively brittle, and difficult to work. It was used -to build large structures such as bridges, and for cannons, cookware, -and engine cylinders. Carbon steel has medium carbon content (0.25% -to 2.1%), and intermediate properties: moderately hard and also tough, -somewhat resistant to corrosion. It is now used for most of the purposes -previously satisfied by wrought iron and many of those of cast iron, -but has historically been especially important for its use in swords, -armour, skyscrapers, large bridges, and machines. - -Historically, the first form of iron to be refined was wrought iron, -produced from ore by a low-temperature furnace process in which the -ore/iron remains solid and impurities (slag) are progressively removed. -Cast iron, by contrast, was produced somewhat later by a high-temperature -process in a blast furnace, in which the metal is melted, and carbon is -unavoidably incorporated from the furnace's fuel. (In fact, it's done -in two stages, first producing pig iron from ore, and then remelting the -pig iron to cast as cast iron.) Carbon steel requires a more advanced -process, in which molten pig iron is processed to remove the carbon, -and then a controlled amount of carbon is explicitly mixed back in. -Other processes are possible to refine iron ore and to adjust its -carbon content. - -Unfortunately, Minetest doesn't let us readily distinguish between -low-temperature and high-temperature processes: in the default game, the -same furnace is used both to cook food (low temperature) and to cast metal -ingots (varying high temperatures). So we can't sensibly have wrought -iron and cast iron produced by different types of furnace. Nor can -furnace recipes discriminate by which kind of fuel is used (and thus -by the availability of carbon). The alloy furnace allows for explicit -alloying, which appropriately represents how carbon steel is made, but -is not sensible for the other two, and is a relatively advanced process. -About the only option to make a second iron-processing furnace process -readily available is to cook multiple times; happily, this bears a slight -resemblance to the real process with pig iron as an intermediate product. - -The default mod's refined iron, which it calls "steel", is identified -with this mod's wrought iron. Cooking an iron lump (representing ore) -initially produces wrought iron; the cooking process here represents a -low-temperature bloomery process. Cooking wrought iron then produces -cast iron; this time the cooking process represents a blast furnace. -Alloy cooking wrought iron with coal dust (carbon) produces carbon steel; -this represents the explicit mixing stage of carbon steel production. -Additionally, alloy cooking carbon steel with coal dust produces cast -iron, which is logical but not very useful. Furthermore, to make it -possible to turn any of the forms of iron into any other, cooking carbon -steel or cast iron produces wrought iron, in an abbreviated form of the -bloomery process. As usual for metals, the same cooking and alloying -processes can be performed in parallel forms on ingots or dust.