墨小客s
Aluminum potassium sulfate preparation and crystal growthOne, the purpose of the experiment1 understand the principle and process of producing aluminum sulfate;2 further understanding of the Al and Al (OH) 3 sexes;3 education principles and methods of crystals from solution.Two, the experimental principleThe sulfate aluminum with alkali metal (K2SO4) forming aluminum potassium sulfate salt.Aluminum potassium sulfate (K2SO4 · Al2 (SO4) 3 · 24H2O) commonly known as alum, it is a kind of colorless crystals, Yi Rong in the water, and the hydrolysis of Al (OH) 3 casse. It has a strong absorption performance, aluminum salt industry is important, as water purifying agent, filling agent in papermaking etc..This experiment using aluminum dissolved in sodium hydroxide solution, four hydroxy aluminum acid sodium production of soluble metal aluminum, otherimpurities are insoluble, filter to remove impurities. Then using H2SO4 to regulate the pH value of the solution for 8-9, namely Al (OH) 3 precipitate,separation, adding H2SO4 in the precipitation, the Al (OH) 3 into Al2 (SO4) 3,and then made into Al2 (SO4) 3 crystals, Al2 (SO4) 3 crystal and K2SO4 crystalrespectively into saturated solution, mixing with alum generated. The reaction is as follows:2Al + 2NaOH + 6H2O = 2Na[Al (OH) 4] + 3H2[Al (OH) 4]+ H+ = Al (OH) 3 + H2O2Al (OH) 3 + 3H2SO4 = Al2 (SO4) 3 + 6H2OAl2 (SO4) 3 + K2SO4 + 24H2O = K2SO4 · Al2 (SO4) 3 · 24H2OCultivation of alum crystal: when there is K2SO4 · Al2 (SO4) 3 · 24H2O crystal precipitation, filtering to obtain crystal, choose structured as a seed, put in the filtrate, the upper dish, let the solution of natural evaporation, crystallization will gradually grow up, become a large single crystal, crystal has eight surface morphology. In order to make the seeds grow large single crystal, it is important not to solution temperature change is too big, make water slow evaporation. In addition to grow large crystals, crystal system can also be generated with the nylon rope, suspended in solution. Such crystals in the growth rate is not affected, the crystals formed more rules.Three, experimental equipmentApparatus and materials: beaker, electronic scales, funnel, the evaporating dish,alcohol lamp, three tripod, asbestos, matches, glass funnel, cylinder, filter paper,pH paper, nylon line.Reagents: Al chip (C.P), NaOH (C.P), K2SO4 (C.P), H2SO4 (3mol · L - 1, 1:1),BaCl2 (0.1 mol · L - 1).Four, the experimental steps1.Al (OH) 3 generationTake 2.3 grams of NaOH solid, into a 200mL beaker, add 30mL distilled water solution. Take 1 grams of aluminum scrap, in batches into the solution (reaction,prevent spills, should be carried out in a fume hood), to no longer have bubbles,indicating the reaction is completed, and then adding distilled water, the volume is about 40mL, filtration. The filtrate into a 200mL beaker, heated to boiling, withcontinuous stirring, add 3mol · L - 1H2SO4, the solution of pH 8 - 9, continue to stir boiled a few minutes, and then filtration, washing and precipitation with boiling water, until the washing liquid pH value reduced to about 7, dry.2.Al2 (SO4) 3 preparationThe prepared Al (OH) 3 into the beaker, under continuous stirring, adding 1:1,H2SO4, and water bath heating. When the solution became clear, stop adding sulfuric acid, Al2 (SO4) 3 solution. The concentrated solution for the 1/2 of the original volume, removed, water cooling to room temperature, the crystallization,filtration, the crystal blot with the filter paper, weighing.Culture and crystal 3 alum systemThe weighing of the aluminum sulfate crystal is arranged on the small beaker,with saturated solution at room temperature. The other weigh K2SO4 solid, alsowith the same volume of saturated solution, and then an equal volume of twosaturated solution phase mixing, stirring evenly. After placement, there will bealum crystal precipitation. Select the filter, structured as a seed, put in thefiltrate, the upper dish, let the solution of natural evaporation, crystallization will gradually grow up, become a large single crystal, crystal has eight surfacemorphology.In order to make the seed generation of large single crystal, it is important not tosolution temperature change is too big, make water slow evaporation. To generate a large crystal, crystal system can also be generated with the nylon rope, suspended in solution. Such crystals in the growth rate is not affected.
Dana是天枰座
Cultivation and preparation of potassium aluminum sulfate crystalsFirst, the purpose of the experiment1 . Learn from the principle of the preparation of aluminum and aluminum potassium sulfate process ;2 . Further understanding of Al and Al (OH) 3 sexes ;3 . Principles and methods of learning in the crystals from the solution.Second, the experimental principleAluminum sulfate with an alkali metal sulfate (K2SO4) and potassium aluminum sulfate and generated salts.Aluminum potassium sulfate (K2SO4 · Al2 (SO4) 3.24 H2O) , commonly known as alum, which is a colorless crystals , soluble in water and hydrolysis of Al (OH) 3 gel precipitation. It has strong adsorption properties is an important aluminum industry, can be used as purifying agent , paper filling agent for many purposes .The experiment was dissolved in sodium hydroxide solution using the aluminum metal , aluminum hydroxy generated four soluble sodium aluminum impurities in the remaining insoluble impurities removed by filtration . H2SO4 followed by adjusting the pH of the solution was 8-9 , i.e. with Al (OH) 3 precipitate , after separation , the precipitate was added H2SO4 , that the conversion of 3 Al2 (SO4) 3 Al (OH), then formed Al2 (SO4) 3 crystals, Al2 (SO4) 3 K2SO4 crystals and crystals were saturated solution , after mixing, have generated alum . About the reaction is as follows :2Al + 2NaOH + 6H2O === 2Na [Al (OH) 4] + 3H2[Al (OH) 4] - + H + === Al (OH) 3 + H2O2Al (OH) 3 + 3H2SO4 === Al2 (SO4) 3 + 6H2OAl2 (SO4) 3 + K2SO4 + 24H2O === K2SO4 · Al2 (SO4) 3.24 H2OAlum monocrystalline culture : When there K2SO4 · Al2 (SO4) 3.24 H2O after precipitation of crystals , the crystal was filtered , structured as a selected seed crystals in the filtrate, and covered with a watch glass , allowing the natural evaporation of the solution , crystallization will gradually grow to become a large single crystal , single crystals with octahedral crystal form . The seed crystal to be grown as a single crystal , it is important not to change the temperature of the solution is so large that the water solution was slowly evaporated. Also to be grown crystals can also be generated on the crystal system of nylon rope , suspended in solution. Such crystal growth rate is not affected in all respects , to generate a more regular crystals .Third, experimental suppliesInstruments and Materials : beakers, electronic scales, Buchner funnel , evaporating dish , alcohol lamp , tripod, asbestos network , matches, glass funnel , graduated cylinder , filter paper , pH test strips, nylon cord.Reagents : Al crumbs (CP), NaOH (CP), K2SO4 (CP), H2SO4 (3mol · L-1, 1:1), BaCl2 (0.1 mol · L-1).Fourth, the experimental procedure1 . Al (OH) 3 is generatedWeigh 2.3 g of solid NaOH , placed in 200mL beaker, add 30mL distilled water . Weigh 1 g of aluminum shavings in batches into the solution ( violent reaction against spills , should be carried out in a fume hood ) , to no more bubbles , and the reaction is completed, then add distilled water to bring the volume to approximately 40mL , filtration . The filtrate was transferred to 200mL beaker and heated to boiling , under continuous stirring , a solution of 3mol · L-1H2SO4, the pH of the solution is 8-9 , and stirring was continued for several minutes to boil , then suction filtered and the precipitate washed with boiling water until the pH value of the washing liquid is reduced to about 7 dry.2 . Preparation of Al2 (SO4) 3 inThe resulting Al (OH) 3 into a beaker with constant stirring , was added 1:1 H2SO4, and water bath . When the solution becomes clear, stop the addition of sulfuric acid to give Al2 (SO4) 3 solution . The solution was concentrated to one half of the original volume , removed, cooled to room temperature and washed with water until crystallization was complete, filtered, the crystals were blotted dry with filter paper and weighed .3 . Preparation and training of large crystals of alumAluminum sulfate crystals weighed into a small beaker, dubbed a saturated solution at room temperature. Another Weigh K2SO4 solid , also dubbed the same volume of a saturated solution , and then an equal volume of a saturated solution of the two -phase mixture, stirring well. After standing , alum crystals will be precipitated. Filtration , elected structured as a seed , on the filtrate , cover the surface of the pan, allow the solution to natural evaporation, crystallization will gradually grow to become a large single crystal , single crystals with octahedral crystal form .In order to generate a large single crystal seed , it is important not to change the temperature of the solution is so large that the water solution was slowly evaporated. To generate large crystal , the crystal can also be generated on the system nylon rope suspended in the solution. Thus in all aspects of the crystal growth rate is not affected .
张小天11
明矾的化学名是十二水硫酸铝钾
外观为透明无色无味的晶体，溶于水呈酸性，本身性寒有毒。工业应用中，常用明矾容易和小苏打配比制作成干粉灭火器，也有用于做缓冲剂，主要用于硫酸盐镀锌时，缓冲镀液的酸碱值。
明矾的作用
在食品领域，明矾可用作发酵粉，净水剂，膨化剂等，还可以作为中药。中医认为，明矾有抗菌和收敛作用，可内服亦可外敷，但因其毒性较大，一般选择外敷，常用于治疗十二指肠溃疡，高脂血症等疾病。
扩展资料：
明矾的危害
其实明矾一般都是作为一种食品添加剂的，明矾中是含有重金属铝元素，铝元素在人体被吸收之后是非常难以排出体外的，一直残留在体内会影响到人体的骨骼，肝脏，脑，睾丸等处，大量的铝元素聚集会影响到人体的大脑以及神经细胞，同时还会导致人体出现脑萎缩，老年性痴呆等等。
明矾对于儿童的影响也是非常大的，不仅会影响到儿童骨骼的生长，同时还会引起婴幼儿的神经发育，甚至还会导致婴幼儿的智力发育障碍，所以大家一定要特别重视，铝元素的聚集会有一个过程，刚开始不容易被忽视，一旦发现后果是非常严重的，几乎就非常难以恢复了。
国家命令禁止在面点和膨化食品中添加明矾
鉴于明矾的各种危害，在我们国家已经明令禁止了，在膨化食品面条还有馒头，油条等，食品的加工过程当中是不可以添加含铝食品添加剂，长期食用明矾对人体危害是相当大的，所以特别要重视。
参考资料：百度百科——十二水硫酸铝钾
薇儿的悲伤
十二水合硫酸铝钾，又称：明矾、白矾、钾矾、钾铝矾、钾明矾，是含有结晶水的硫酸钾和硫酸铝的复盐。
西医作用：
1、抗菌作用明矾对多种革兰阴性、阳性球菌和杆菌都有抑制作用；对常见化脓菌有较强抑菌作用．实验表明：明矾对金黄色葡萄球菌、变形杆菌有抑制作用（试管法）。
对大肠杆菌、绿脓杆菌、炭疽杆菌、弗氏和志贺痢疾杆菌、伤寒杆菌和副伤寒甲杆菌、变形杆菌及葡萄球菌等有抑制作用（纸碟、平板法）；对绿色链球菌、溶血性链球菌、肺炎球菌、白喉杆菌作用最强，对牛型布氏杆菌、百日咳杆菌、脑膜炎球菌作用次之，对流感杆菌无作用（纸片法）。
高浓度明矾液对人型（H37RV）及牛型结核杆菌也有抑制作用．临床上用0.75%枯矾混悬液对控制烧伤创面的绿脓杆菌感染有效。
体外实验表明：白矾及枯矾对羊毛状小孢子菌和红色毛癣菌有很强的抑制作用。
2、收敛、固脱作用实验证明：明矾水具有很强的收敛作用．明矾内服刺激性很大，故多外用，可止汗；也可治疗白带过多及溃疡（浓度为1%～5%）。
明矾注射液、明矾液和硫酸铝液对大鼠离体直肠，均有明显的抑制作用．浓度超过4%～6%时，可发生蛋白凝固变性，使直肠失去蠕动功能。
8%明矾液注射于直肠周围后，可使浆膜及平滑肌凝固性坏死，继而形成无菌性黏连，从而使直肠各层和直肠与周围组织固定，直肠不再滑脱．有报告认为，局部用4%明矾溶液对动物子宫脱垂亦有一定的作用。
3、抗阴道滴虫的作用10%明矾液在试管内（培养液与药液之比为 1：1）有明显的抗阴道滴虫作用。
4、凝固蛋白的作用明矾与蛋白质相遇，使成难溶性的化合物而沉淀．明矾水在体外能使血清立即沉淀，有强烈凝固蛋白的作用．该品可用于止血，如鼻衄时可用棉球浸饱和的明矾溶液塞于鼻孔。
有报告认为，明矾、儿茶内服能治疗肺结核咯血．用白矾、郁金配成的白金丸对家兔实验性高脂血症有效。
5、利胆作用：白矾0.6g/kg十二指肠给药，对麻醉大鼠明显增加胆汁流量。
6、局部刺激作用：局部刺激性很大，局部注射15%溶液0.3-0.5ml，使兔狂躁不安，局部红肿、破溃，0.3ml静脉注射，使兔发生寒颤、呼吸急迫，末梢血管变紫色，呈缺氧现象。
中医作用：
1、《纲目》：矾石之用有四：吐利风热之痰涎，取其酸苦涌泄也；治诸血痛，脱肛，阴挺，疮疡，取其酸涩而收也；治痰饮，泄痢，崩、带，风眼，取其收而燥湿也；治喉痹痈疽，蛇虫伤螫，取其解毒也。
2、《本草经疏》：矾石，味酸气寒而无毒，其性燥急收涩，解毒除热坠浊。盖寒热泄痢，皆湿热所为，妇人白沃，多由虚脱，涩以止脱故也。
阴蚀恶疮，亦缘湿火，目痛多由风热。除固热在骨髓坚齿者，髓为热所劫则空，故骨痿而齿浮，矾性入骨除热，故亦主之。去鼻中息肉者，消毒除热燥湿之功也。白矾，《本经》主寒热泄痢，此盖指泄痢久不止，虚脱滑泄，因发寒热。
矾性过涩，涩以止脱，故能主之。假令湿热方炽，积滞正多，误用收涩，为害不一，慎之。妇人白沃多由虚脱，故用收涩以固其标，终非探本之治。
目痛不由胬肉及有外障，亦非所宜。除固热在骨髓，仅可资其引导，若谓其独用，反有损也。矾性燥急，而能劫水，故不利齿骨，齿者骨之余故也。
3、《长沙药解》：矾石，入足太阴脾、足太阳膀胱经，善收湿淫，最化瘀浊，黑疸可消，白带能除。《金匮》矾石丸治妇人带下经水闭不利，藏坚癖不止，中有干血，下白物。矾石化败血而消痞硬，收湿淫而敛精液，杏仁破其郁陷之滞气也。硝矾散治女劳黑疸，以其燥湿而利水也。
《千金》矾石丸治脚气冲心，以其燥湿也。矾石酸涩燥裂，最收湿气而化瘀腐，善吐下老痰宿饮，缘痰涎凝结，粘滞于上下窍隧之间，牢不可动，矾石收罗而扫荡之，离根失据，藏府不容，高者自吐，低者自下，实非吐下之物也。
其善治痈疽者，以中气未败，痈疽外发，肉腐脓泄，而新肌生长，自无余事，阳衰土湿，中气颓败，痈疽不能外发，内陷而伤府藏，是以死也，矾石收藏府之水湿，土燥而气达，是以愈也。
4、《本经》：主寒热泄痢，白沃，阴蚀恶疮，目痛，坚骨齿。
5、《别录》：除固热在骨髓，去鼻中息肉。
6、《药性论》：治鼠漏，瘰疬，疗鼻衄，生含咽津，治急喉痹。
7、《日华子本草》：除风去劳，消痰止渴，暖水藏。治中风失音，疥癣。和桃人、葱汤浴，可出汗。
8、《本草衍义》：火枯为粉，贴嵌甲，牙缝中血出如衄者，贴之办愈。
9、《本草蒙筌》：禁便泻，塞齿疼，洗脱肛涩肠，敷脓疮收水。
10、《医学入门》：治耳卒肿出脓，目赤，目翳，胬肉，口舌生疮，牙齿肿痛出血，历久碎坏欲尽，急喉风痹，心肺烦热，风涎壅盛，作渴泄痢。兼治蛇蝎、恶犬、壁镜、驴涎、马汗毒伤。
11、《医林纂要》：生用解毒，煅用生肌却水。
制备方法：
1、天然明矾石加工法将明矾石破碎、经焙烧、脱水、风化、蒸汽浸取、沉降、结晶、粉碎，制得硫酸铝钾成品。
2、铝矾土法用硫酸分解铝矾土矿生成硫酸铝溶液，再加硫酸钾反应，经过滤、结晶、离心脱水、干燥制得硫酸铝钾产品
3、重结晶法粗明矾加水煮沸、蒸发、结晶、分离、干燥制得硫酸铝钾成品。
4、氢氧化铝法将氢氧化铝溶于硫酸，再加入计量的硫酸钾溶液加热反应、经过滤、浓缩、结晶、离心分离、干燥、制得硫酸铝钾成品。
5、将18.37g硫酸钾溶于70g 100℃的水中，另将70.24g十八水硫酸铝Al2(SO4)3·18H2O溶于60g 100℃的水中。趁热将这两种溶液混合，在不停的搅拌下使混合液慢慢冷却。当溶液冷却到20℃时，可获得约85g十二水硫酸铝钾的结晶。
6、采用重结晶法。将工业品硫酸铝钾加水溶解，然后经净化、除杂质、过滤、浓缩、结晶、离心脱水、干燥，制得硫酸铝钾。
7、原料产地：中国产地有安徽省庐江矾矿等。浙江苍南县矾山镇因蕴藏丰富的明矾矿石而被誉为“世界矾都”。它的明矾矿石储量约占世界60%、中国80%，矿藏分布在相邻的五条矿带上。
应用领域：
1、工业应用
灭火剂：
干粉灭火器内盛有约1mol/L的明矾溶液和约1mol/L的NaHCO3（小苏打）溶液（还有起泡剂），两种溶液的体积比约为11：2。明矾过量是为了使灭火器内的小苏打充分反应，释放出足量的二氧化碳，以达到灭火的目的。
膨化剂：
炸油条（饼）或膨化食品时，若在面粉里加入小苏打后，再加入明矾，则会加快二氧化碳的产生，大大加快了膨化的速度。这样就可以使油条（饼）在热油锅中一下子就鼓起来，得到香脆可口的油条（饼）了。
缓冲剂：
在硫酸盐镀锌中可用作缓冲剂，以稳定镀液的ph值。硫酸铝钾用于硫酸盐镀锌、刷镀锌和镁合金的化学氧化，也可用作处理污水的凝聚剂，若用于镀锌需要注意其铁和重金属的含量。 [5]
2、药物功能
明矾性寒味酸涩，具有较强的收敛作用。中医认为，明矾具有解毒杀虫，燥湿止痒，止血止泻，清热消痰的功效抗阴道滴虫等作用。一些中医用明矾来治疗高脂血症、十二指肠溃疡、肺结核咯血等疾病。
3、食用功能
明矾还可用于熬绿豆稀饭，主要作用是使绿豆更容易被煮烂但不推荐这样作原因是不好控制用量有可能中毒可以用食用碱代替。
明矾还可用于制备铝盐、油漆、鞣料、媒染剂、造纸、防水剂等。
净水作用：明矾溶于水后电离产生了Al3+，Al3+与水电离产生的OHˉ结合生成了氢氧化铝，氢氧化铝胶体粒子带有正电荷，与带负电的泥沙胶粒相遇，彼此电荷被中和。失去了电荷的胶粒，很快就会聚结在一起，粒子越结越大，终于沉入水底。这样，水就变得清澈干净了。
4、明令禁止
油条、馒头、面条、膨化食品等食品在加工过程中可能会使用含铝食品添加剂，长期食用对人体伤害很大，尤其对儿童生长发育和智力都会造成影响。
国家卫计委等五部门规定，从2014年7月1日起，馒头、发糕等面制品(除油炸面制品、挂浆用的面糊、裹粉、煎炸粉外)不能添加含铝膨松剂硫酸铝钾和硫酸铝铵，也就是俗称的“明矾”，复合型膨松剂(即泡打粉)的主要成分也是上述两种物质。膨化食品中，不再允许使用任何含铝食品添加剂。
百度百科-十二水硫酸铝钾
